Mushroom Emperors [Discontinued] by Mushroom Wisdom

Allergic rhinitis (hay fever). Oral agaricus mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in people with IgE-positive birch pollen allergy shows that taking a specific agaricus mushroom product (Andosan, Immunopharma) containing 82% agaricus mushroom, 15% Hericium erinaceus mushroom, and 3% maitake mushroom extracts, 60 mL daily for 7 weeks starting before the pollen season, reduces symptoms of allergic rhinitis and allergic asthma and decreases use of anti-allergy medications when compared with placebo. During the allergy season, birch-specific IgE levels were reduced, and basophils were less sensitive to allergen activation (102919).
Cancer. Although there is interest in using oral agaricus mushroom for the treatment of various types of cancer, there is insufficient reliable information about the clinical effects of agaricus mushroom for this purpose. Cardiovascular disease (CVD).Although there is interest in using oral agaricus mushroom for the management of CVD and CVD risk factors, there is insufficient reliable information about the clinical effects of agaricus mushroom for this purpose.
Chemotherapy-induced adverse effects. It is unclear if oral agaricus mushroom is beneficial for reducing adverse effects in patients undergoing chemotherapy treatment. Details: Preliminary clinical research in females with gynecologic cancers shows that taking an agaricus mushroom extract three times daily while receiving chemotherapy for 6 weeks might improve some of the adverse effects of chemotherapy, such as generalized weakness, decreased appetite, and emotional instability, when compared with chemotherapy alone (15404).
Crohn Disease. It is unclear if oral agaricus mushroom is beneficial for Crohn disease. Details: Preliminary clinical research in patients with Crohn disease shows that taking an oral agaricus mushroom extract (AndoSan, ACE Co. Ltd.) 30 mL twice daily for 21 days does not improve fatigue, quality of life, or symptom severity when compared with placebo (94721).
Diabetes. It is unclear if oral agaricus mushroom is beneficial for type 2 diabetes. Details: Preliminary clinical research in patients with type 2 diabetes shows that taking an agaricus mushroom extract 500 mg orally three times daily for 12 weeks, in combination with metformin and the sulfonylurea gliclazide, decreases insulin resistance and lowers fasting insulin levels more than metformin and gliclazide alone (15421).
Hepatitis B. It is unclear if oral agaricus mushroom is beneficial for hepatitis B. Details: Preliminary clinical research in adults with chronic hepatitis B infection shows that taking agaricus mushroom extract 500 mg three times daily for 12 months decreases aspartate aminotransferase (AST) from 246 IU/L to 61 IU/L and alanine aminotransferase (ALT) from 151 IU/L to 46 IU/L (94719). However, these results are limited by small study size and the lack of a comparator group.
Hyperlipidemia. Although there is interest in using oral agaricus mushroom for hyperlipidemia, there is insufficient reliable information about the clinical effects of agaricus mushroom for this condition.
Multiple myeloma. It is unclear if oral agaricus mushroom is beneficial for multiple myeloma. Details: Preliminary clinical research in patients with multiple myeloma undergoing stem cell transplantation with high-dose chemotherapy shows that taking an agaricus mushroom extract (AndoSan, ACE Co. Ltd.) 60 mL orally daily for about 7 weeks during chemotherapy does not improve treatment response or overall survival when compared with placebo (94716).
Osteoporosis. Although there is interest in using oral agaricus mushroom for osteoporosis, there is insufficient reliable information about the clinical effects of agaricus mushroom for this condition.
Peptic ulcers. Although there is interest in using oral agaricus mushroom for peptic ulcers, there is insufficient reliable information about the clinical effects of agaricus mushroom for this condition.
Ulcerative colitis. It is unclear if oral agaricus mushroom is beneficial for ulcerative colitis. Details: Preliminary clinical research in patients with symptomatic ulcerative colitis shows that taking an agaricus mushroom extract (AndoSan, ACE Co. Ltd.) 30 mL orally twice daily for 21 days improves fatigue, quality of life, and overall symptom scores when compared with placebo (94715). More evidence is needed to rate agaricus mushroom for these uses.

BLACK HOOF MUSHROOM (Meshima (Phellinus linteus) fruiting body extract)

Coronavirus disease 2019 (COVID-19). Although there has been interest in using oral black hoof mushroom for COVID-19, there is insufficient reliable information about the clinical effects of black hoof mushroom for this purpose. More evidence is needed to rate black hoof mushroom for this use.

Cardiovascular disease (CVD). Although there is interest in using oral chaga for CVD, there is insufficient reliable information about the clinical effects of chaga for this condition.
Coronavirus disease 2019 (COVID-19). Although there has been interest in using oral chaga for COVID-19, there is insufficient reliable information about the clinical effects of chaga for this purpose.
Diabetes. Although there is interest in using oral chaga for diabetes, there is insufficient reliable information about the clinical effects of chaga for this condition. More evidence is needed to rate chaga for these uses.

CORDYCEPS (Cordyceps (Cordyceps sinensis) mycelium powder)

Athletic performance. Taking cordyceps orally does not seem to improve athletic performance in adults. Details: One small clinical study in endurance-trained cyclists shows that taking a specific mycelial fermentation product of cordyceps (CordyMax Cs-4) 3.15 grams daily for 5 weeks does not improve endurance time trials or aerobic capacity when compared with placebo (12095). Another small study in healthy elderly adults shows that taking the same cordyceps preparation (CordyMax Cs-4) 3 grams daily for 12 weeks does not improve exercise performance when compared with placebo (46120). Research also shows that taking combination products containing cordyceps and other ingredients does not improve athletic performance when compared with control. These products have combined cordyceps (CordyMax Cs-4) 1000 mg with rhodiola 300 mg (46091) or cordyceps (CordyMax Cs-4) 2000 mg with roseroot 600 mg (Optygen, First Endurance) (15573); liquid and powdered cordyceps formulations with reishi mushroom, shiitake mushroom, bamboo, and honey (Fohow oral liquid and Fohow lingzhi capsules, FOHOW Technology Investment Group Co. Ltd.) (98686); and cordyceps (form unknown) 1.2 grams with a 930 mg mixture of extracts of ashwagandha root, green tea leaf, rhodiola root, and astragalus root (Shroom Tech Sport, Onnit Labs) (105079).

Arrhythmia. Although there is interest in using oral cordyceps for arrhythmia, there is insufficient reliable information about the clinical effects of cordyceps for this condition.
Asthma. Oral cordyceps has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in children with asthma shows that a 619 mg capsule containing equal weights of the dried aqueous extracts of cordyceps, astragalus, skullcap, Radix stemonae, and Bulbus fritillariae daily for 6 months does not reduce the need for medication or improve symptoms when compared with placebo (32935).
Autoimmune thyroiditis. Oral cordyceps has only been evaluated in combination with other treatmentss; its effect when used alone is unclear. Details: A meta-analysis of low-quality clinical studies in China in patients with Hashimoto's thyroiditis shows that taking cordyceps up to 9 grams daily for up to 28 weeks in addition to a low-iodine diet or levothyroxine decreases circulating thyroid antibody levels including thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb) when compared with a low-iodine diet or levothyroxine treatment alone. In the subgroup of patients with hypothyroidism, taking cordyceps with levothyroxine increases free thyroxine (FT4) but does not affect free triiodothyronine (FT3) or thyroid-stimulating hormone (TSH) levels when compared with levothyroxine alone. (113622).
Chronic kidney disease (CKD). Small clinical studies suggest that oral cordyceps may modestly improve biomarkers in some patients with CKD. Details: A meta-analysis of clinical research in patients in China with CKD shows that taking cordyceps 0.6-2 grams orally three times daily, along with standard treatment, seems to decrease serum creatinine levels by 0.6 mg/dL and increase creatinine clearance by 9.2 mL/min when compared with standard treatment alone (92829). Another meta-analysis of clinical studies in patients in China with diabetic kidney disease shows that taking cordyceps 0.5-2 grams orally three times daily along with angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) decreases blood urea nitrogen by 2 mg/dL and decreases serum creatinine levels by 0.1 mg/dL when compared with ACEI/ARB treatment alone (92830). Most individual studies in these analyses used Bailing (Cs-C-Q80) or Jinshuibao (Cs-4), fermented cordyceps mycelial products (92829,92830). Both of these analyses are limited by the low methodological quality and short duration (usually 1-6 months) of most of the included studies.
Chronic obstructive pulmonary disease (COPD). Preliminary clinical studies suggest that oral cordyceps may modestly improve symptoms of COPD. Details: A meta-analysis of preliminary clinical research in patients with moderate or severe COPD shows that taking cordyceps alone or as part of a formulation containing other products for up to 12 months improves lung function and reduces the incidence of an acute exacerbation by a small amount. Also, the distance walked in 6 minutes is increased by about 45 meters, which was considered clinically meaningful. Most individual studies in this analysis used Bailing (Cs-C-Q80) or Jinshuibao (Cs-4), fermented cordyceps mycelial products, in combination with conventional treatments with conventional treatments alone (109705). This analysis is limited by the low methodological quality of the included studies.
Contrast induced nephropathy. Small clinical studies suggest that oral cordyceps may modestly reduce contrast induced nephropathy. Details: A preliminary clinical study in patients with diabetic nephropathy shows that taking a specific cordyceps mycelial product (Corbrin; CS-C-Q80) 2-3 grams orally three times daily for 3 days before and after angiography reduces the risk of contrast induced nephropathy by about 48% to 66% when compared to standard treatment (92827). However, other preliminary clinical research in patients with stable angina pectoris shows that taking the same cordyceps product 3 grams orally three times daily for 3 days before and after angioplasty does not decrease the prevalence of contrast induced nephropathy when compared to standard therapy (92826). Reasons for these discrepancies are not clear but may relate to the small size and heterogenous populations in these studies.
Diabetic nephropathy. Early research suggests that oral cordyceps may modestly improve kidney function in patients with diabetic kidney disease. Details: A meta-analysis of low to moderate quality clinical research in patients with diabetic kidney disease shows that taking cordyceps as adjunctive therapy to angiotensin-converting enzyme inhibitors or angiotensin receptor blockers for 2-24 weeks modestly improves kidney function when compared to these medications alone. Kidney function was based on markers such as blood creatinine and urea nitrogen, as well as urinary albumin and total protein. There were also modest improvements in systolic and diastolic blood pressure, triglycerides, and low-density lipoprotein (LDL) cholesterol. There was no effect on glycemic indices. The effect of cordyceps on disease progression or cardiovascular events is unclear (111903).
Cough. Although there is interest in using oral cordyceps for cough, there is insufficient reliable information about the clinical effects of cordyceps for this purpose.
Fatigue. Although there is interest in using oral cordyceps for fatigue, there is insufficient reliable information about the clinical effects of cordyceps for this purpose.
Hepatitis B. Although there is interest in using oral cordyceps for hepatitis B, there is insufficient reliable information about the clinical effects of cordyceps for this condition.
Hypercholesterolemia. Although there is interest in using oral cordyceps for hypercholesterolemia, there is insufficient reliable information about the clinical effects of cordyceps for this condition.
Kidney failure. Small clinical studies suggest that oral cordyceps may improve inflammatory markers in patients on hemodialysis. Details: A meta-analysis of small clinical trials in patients in China on hemodialysis suggests that adding cordyceps to standard treatment does not seem to improve serum creatinine levels but may improve certain markers of inflammation, such as C-reactive protein, when compared with placebo. Most individual studies in this analysis used Bailing (Cs-C-Q80) or Jinshuibao (Cs-4), fermented cordyceps mycelial products (105076).
Kidney transplant. Small clinical studies suggest that oral cordyceps is no better than standard treatment in patients with kidney transplant. Details: A meta-analysis of 4 heterogeneous clinical trials evaluating patients in China immediately post-kidney transplant or patients with complications post-kidney transplant suggests that adding cordyceps to standard therapy with cyclosporine and steroids is no better than adding azathioprine 50-150 mg for improving overall survival or graft survival or reducing rejection risk. However, there was a non-significant trend to reduced risk of graft rejection in the cordyceps group (95905). A higher quality systematic review, which determined the available studies were too heterogeneous to pool together in a meta-analysis, suggests that adding cordyceps 3-6 grams to standard therapy daily is no better than azathioprine or cyclosporine for improving organ rejection, kidney function, or survival in patients after kidney transplant (92828). All individual studies in these analyses used Bailing (Cs-C-Q80) fermented cordyceps mycelial product (95905,92828).
Sexual dysfunction. It is unclear if oral cordyceps is beneficial in patients with sexual dysfunction. Details: Preliminary clinical research shows that taking a specific mycelial fermentation product of cordyceps (CordyMax Cs-4) approximately 3 grams daily for 40 days can improve symptoms of hyposexuality in 66% of patients, compared with 32% of patients taking natural cordyceps and 24% of patients taking placebo (46145).
Tinnitus. Although there is interest in using oral cordyceps for tinnitus, there is insufficient reliable information about the clinical effects of cordyceps for this condition. More evidence is needed to rate cordyceps for these uses.

LION'S MANE MUSHROOM (Lion's Mane (Hericium erinaceus) fruiting body powder, Lion's Mane fruiting body standardized extract)

MAITAKE MUSHROOM (Maitake fruiting body powder, Maitake fruiting body standardized extract, Maitake fruiting body standardized extract)

Alzheimer disease. It is unclear if oral lion's mane mushroom is beneficial in patients with Alzheimer disease. Details: Preliminary clinical research in patients over 50 years of age with mild Alzheimer disease shows that taking lion's mane mushroom mycelia (standardized to contain 5 mg/gram of erinacrine A) 1.05 grams daily for 49 weeks improves performance of activities of daily living when compared with placebo. It also improves scores on the Mini-Mental State Examination when compared with baseline (105546). The validity of these findings is reduced by the lack of an intention to treat analysis, and the comparison of some outcomes to baseline instead of placebo.
Anxiety. Although there is interest in using oral lion's mane mushroom for anxiety, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Athletic performance. Although there is interest in using oral lion's mane mushroom for improving athletic performance, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this purpose.
Cancer. Although there is interest in using oral lion's mane mushroom for cancer, there is insufficient reliable information about the clinical effects of lions mane mushroom for this purpose.
Cognitive function. Small clinical trials suggest that lion's mane mushroom does not improve cognitive function. Details: A small clinical trial shows that taking lion's mane mushroom 3.2 grams daily for 12 weeks does not improve most measures of cognitive function when compared with placebo in middle aged to older adults (101770). Additional clinical research in younger adults shows that taking lion's mane mushroom 10 grams daily for 4 weeks does not improve markers of cognition during a period of exercise-induced fatigue when compared with taking placebo. The lion's mane product is 50% dried mushroom and 50% extract (111932). These studies were small and may have been underpowered to detect differences.
Cognitive impairment. It is unclear if oral lion's mane mushroom is beneficial in patients with mild cognitive impairment. Details: One clinical study in Japanese patients aged 50-80 years old with mild cognitive impairment shows that taking lion's mane mushroom powder 1 gram three times daily for 16 weeks increases cognitive function when compared with placebo. However, cognitive function regresses within 4 weeks of treatment termination (91999).
Coronavirus disease 2019 (COVID-19). Although there has been interest in using oral lion's mane mushroom for COVID-19, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this purpose.
Dementia. Although there is interest in using oral lion's mane mushroom for dementia, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Depression. It is unclear if oral lion's mane mushroom is beneficial in patients with depression. Details: Preliminary clinical research in perimenopausal patients without a formal diagnosis of depression shows that eating 4 cookies daily, each containing 0.5 grams powdered lion's mane mushroom, for 4 weeks is similarly effective to placebo cookies for reducing scores on a depression scale (105547).
Diabetes. Although there is interest in using oral lion's mane mushroom for diabetes, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Gastritis. It is unclear if oral lion's mane mushroom is beneficial in patients with chronic atrophic gastritis. Details: Preliminary clinical research in patients with chronic atrophic gastritis shows that taking lion's mane mushroom (unknown dose) before meals daily for 3 months improves upper abdominal pain in about 27% more patients, improves dyspepsia in about 39% more patients, and reduces inflammatory infiltration in about 23% more patients when compared with placebo (92630).
Hyperlipidemia. Although there is interest in using oral lion's mane mushroom for hyperlipidemia, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Memory. Although there is interest in using oral lion's mane mushroom for memory, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this purpose.
Multiple sclerosis (MS). Although there is interest in using oral lion's mane mushroom for MS, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Obesity. Although there is interest in using oral lion's mane mushroom for obesity, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Parkinson disease. Although there is interest in using oral lion's mane mushroom for Parkinson disease, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Peptic ulcers. Although there is interest in using oral lion's mane mushroom for peptic ulcers, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition.
Wound healing. Although there is interest in using topical lion's mane mushroom for wound healing, there is insufficient reliable information about the clinical effects of lion's mane mushroom for this condition. More evidence is needed to rate lion's mane mushroom for these uses.

Allergic rhinitis (hay fever). Although there has been interest in using oral maitake mushroom for allergic rhinitis, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Cancer. Although there has been interest in using oral maitake mushroom for cancer, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Chemotherapy-induced anemia. Although there has been interest in using oral maitake mushroom for preventing chemotherapy-induced anemia, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Chemotherapy-induced diarrhea. Although there has been interest in using oral maitake mushroom for preventing chemotherapy-induced diarrhea, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Chemotherapy-related fatigue. Although there has been interest in using oral maitake mushroom for preventing chemotherapy-related fatigue, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Chemotherapy-induced leukopenia. Although there has been interest in using oral maitake mushroom for preventing chemotherapy-induced leukemia, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Chemotherapy-induced nausea and vomiting (CINV). Although there has been interest in using oral maitake mushroom for preventing CINV, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Chronic fatigue syndrome (CFS). Although there has been interest in using oral maitake mushroom for CFS, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Coronavirus disease 2019 (COVID-19). Although there has been interest in using oral maitake mushroom for COVID-19, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Diabetes. Although there has been interest in using oral maitake mushroom for diabetes, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
HIV/AIDS. Although there has been interest in using oral maitake mushroom for HIV/AIDS, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Hyperlipidemia. Although there has been interest in using oral maitake mushroom for hyperlipidemia, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Hypertension. Although there has been interest in using oral maitake mushroom for hypertension, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Laryngeal cancer. It is unclear if maitake mushroom is beneficial for improving quality of life in patients with laryngeal cancer. Details: Clinical research in patients with laryngeal or pharyngeal cancer undergoing chemo-radiation treatment shows that taking maitake mushroom polysaccharides D-fraction 1 gram 3 times daily during treatment modestly improve survival over 5 years and prevents the decline in overall quality of life when compared with taking placebo (111935).
Myelodysplastic syndromes. Although there has been interest in using oral maitake mushroom for myelodysplastic syndromes, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Obesity. Although there has been interest in using oral maitake mushroom for obesity, there is insufficient reliable information about the clinical effects of maitake mushroom for this purpose.
Pharyngeal cancer. It is unclear if maitake mushroom is beneficial for improving quality of life in patients with pharyngeal cancer. Details: Clinical research in patients with laryngeal or pharyngeal cancer undergoing chemo-radiation treatment shows that taking maitake mushroom polysaccharides D-fraction 1 gram 3 times daily during treatment modestly improve survival over 5 years and prevents the decline in overall quality of life when compared with taking placebo (111935).
Polycystic ovary syndrome (PCOS). Maitake mushroom may have some benefit in PCOS, but it does not appear to be as effective as clomiphene. Details: Preliminary clinical research in patients with PCOS shows that taking three tablets of a specific combination product (SX-Fraction, Maitake Products, Inc.), each containing maitake mushroom powder 250 mg plus maitake SX-fraction (a glycoprotein-rich extract) 18 mg, three times daily starting on the first day of menses for up to 28 weeks, can improve ovulation cycle rates, but does not appear to be as effective as clomiphene. After 12 weeks of treatment, patients taking the maitake mushroom product had an ovulatory cycle rate of about 42% compared with about 70% in those taking clomiphene 50 mg daily. However, 13 out of 15 patients who failed monotherapy with maitake mushroom or clomiphene alone ovulated when both maitake mushroom and clomiphene were used for 4 cycles (17131). More evidence is needed to rate the effectiveness of maitake mushroom for these uses.

PORIA MUSHROOM (Poria (Poria cocus) Sclerotium extract)

Cancer. Although there is interest in using oral poria mushroom for cancer, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Chronic fatigue syndrome (CFS). Although there is interest in using oral poria mushroom for CFS, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Chronic kidney disease (CKD). Although there is interest in using oral poria mushroom for CKD, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Coronavirus disease 2019 (COVID-19). Although there has been interest in using oral poria mushroom for COVID-19, there is insufficient reliable information about the clinical effects of poria mushroom for this purpose.
Dementia. Although there is interest in using oral poria mushroom for dementia, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Diabetes. Oral poria mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A meta-analysis of generally small clinical trials in patients with type 2 diabetes shows that taking Chinese herbal medicine combinations containing poria mushroom for 2-24 weeks along with hypoglycemic medications modestly reduces fasting blood glucose and glycated hemoglobin levels when compared with control groups taking hypoglycemic agents only. There were also modest improvements in levels of triglycerides and low-density lipoprotein (LDL) cholesterol and in insulin sensitivity (111920). Given the large number of other ingredients in the available formulations, it is unclear if any beneficial effects are related to poria mushroom, other ingredients in the formulation, or their combination.
Diarrhea. Although there is interest in using oral poria mushroom for diarrhea, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Endometriosis. Although there is interest in using oral poria mushroom for endometriosis, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Influenza. Oral poria mushroom has only been evaluated for influenza vaccine enhancement in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in healthy adults shows that taking a product containing poria mushroom extract, rosemary extract, and aloe gel powder twice daily for 28 days prior to and following an influenza vaccination does not affect upper respiratory tract illness symptoms, severity, duration, or medication-related use when compared with taking placebo (111921). It is unclear if this study was large enough to detect differences between groups. Also, the effect of poria mushroom itself on influenza vaccine enhancement is unclear.
Tinnitus. Although there is interest in using oral poria mushroom for tinnitus, there is insufficient reliable information about the clinical effects of poria mushroom for this condition.
Urinary tract infections (UTIs). Although there is interest in using oral poria mushroom for UTIs, there is insufficient reliable information about the clinical effects of poria mushroom for this use. More evidence is needed to rate poria mushroom for these uses.

REISHI MUSHROOM (Reishi (Ganoderma lucidum) fruiting body double extract)

Hyperlipidemia. Preliminary clinical studies show that oral reishi mushroom does not improve lipid levels in patients with hyperlipidemia or type 2 diabetes. Details: Preliminary clinical research shows that taking reishi mushroom extract 1440 mg daily for 12 weeks does not significantly improve the lipid profile in patients with hyperlipidemia (70776). Also, a meta-analysis shows that taking reishi mushroom extract 1400-4000 mg daily for 12-16 weeks does not reduce total cholesterol or low-density lipoprotein (LDL) cholesterol in patients with type 2 diabetes (91435).

Aging. Although there has been interest in using oral reishi mushroom for aging, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Altitude sickness. Although there has been interest in using oral reishi mushroom for altitude sickness, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Alzheimer disease. A small clinical study suggests that oral reishi mushroom does not improve Alzheimer disease symptoms. Details: Preliminary clinical research in patients with Alzheimer disease shows that taking reishi mushroom powder 1000 mg three times daily for 6 weeks does not improve memory, language skills, or quality of life when compared with placebo (97942).
Asthma. Although there has been interest in using oral reishi mushroom for asthma, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Benign prostatic hyperplasia (BPH). Preliminary clinical research suggests that oral reishi mushroom extract can help reduce some lower urinary tract symptoms in patients with BPH. Details: Clinical research in patients with mild to moderate lower urinary tract symptoms (LUTS) associated with BPH, urinary incontinence, overactive bladder, or other conditions, shows that taking reishi mushroom extract 6 mg orally once daily for up to 12 weeks moderately improves total symptom severity measured on the International Prostate Symptom Score (IPSS) scale, when compared with placebo (91436,91437). A higher dose of 60 mg daily is not more effective than the 6 mg dose, and a lower dose of 0.6 mg daily is not more effective than placebo (91437). Reishi mushroom extract does not improve peak urine flow rate, residual urine volume, prostate volume, or quality of life when compared with placebo (91436,91437). The relevance of these results is unclear since not all of the patients with LUTS had BPH.
Bronchitis. Although there has been interest in using oral reishi mushroom for bronchitis, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Cancer. It is unclear if oral reishi mushroom is beneficial when used in conjunction with chemotherapy. Details: A meta-analysis of 9 clinical trials using various reishi mushroom products in combination with chemotherapy found that complete and partial responses increased by 30% with combination therapy when compared with chemotherapy alone. However, there was no difference in overall survival (102915). The reliability and applicability of these results are unclear since the trials looked at several different types of cancer, used varying doses and durations of therapy, and were all conducted in China or other Asian countries.
Cancer-related fatigue. It is unclear if oral reishi mushroom is beneficial in patients with breast cancer and fatigue. Details: Results from a small clinical study in breast cancer patients show that taking reishi mushroom powder 1000 mg orally three times daily for 4 weeks can improve cancer-related fatigue when compared with placebo (91438). However, it is not clear if the improvement is clinically meaningful.
Cardiovascular disease (CVD). It is unclear if oral reishi mushroom is beneficial for reducing CVD risk factors. Details: A meta-analysis of 5 low-quality studies in adults with diabetes shows that taking reishi mushroom 1400-3000 mg daily for 12-16 weeks does not reduce CVD risk factors, including total and low-density lipoprotein (LDL) cholesterol, triglycerides, blood pressure, and body mass index, when compared with placebo (91435).
Chronic fatigue syndrome (CFS). Although there has been interest in using oral reishi mushroom for CFS, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Chronic kidney disease (CKD). Although there has been interest in using oral reishi mushroom for CKD, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Colorectal adenoma. Limited clinical research suggests that oral reishi mushroom extract may be beneficial for reducing colorectal adenoma size. Details: Preliminary clinical research in patients with colorectal adenomas shows that taking reishi mushroom extract 1500 mg orally in two divided doses daily for 12 months reduces the number and size of adenomas when compared with no treatment (70774).
Coronary heart disease (CHD). It is unclear if oral reishi mushroom is beneficial for CHD. Details: Preliminary clinical research shows that taking a specific reishi mushroom extract (Ganopoly, Encore International Co.) 1800 mg orally three times daily for 12 weeks reduces symptoms of CHD, such as chest pain, palpitations, and shortness of breath, in a greater percentage of patients when compared with placebo (70800).
Diabetes. Evidence on the use of oral reishi mushroom in patients with type 2 diabetes is conflicting. Details: A meta-analysis of clinical research in patients with type 2 diabetes shows that taking reishi mushroom extract 1400-4000 mg daily for 12-16 weeks does not reduce glycated hemoglobin (HbA1c) or plasma lipids (91435). However, one preliminary clinical study in patients with type 2 diabetes shows that taking a specific reishi mushroom extract (Ganopoly, Encore International Co.) 1800 mg three times daily for 12 weeks reduces HbA1c, but not fasting blood glucose, when compared with placebo (70801).
Fibromyalgia. It is unclear if oral reishi mushroom is beneficial for fibromyalgia. Details: A small clinical trial in patients with fibromyalgia shows that taking reishi mushroom (MundoReishi Salud S.L.) powder 3 grams twice daily for 6 weeks does not improve mood, quality of life, anthropometric measures, blood pressure, or glycemic or lipid parameters when compared with placebo (108309,108310). However, the study may have been underpowered to detect any differences between groups.
Genital herpes. Oral reishi mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with recurrent genital herpes shows that taking 4.4 grams of a mixture of hot water extracts of reishi mushroom, terminalia, Job's tears, Wisteria floribunda, Trapa natans, and Elfvingia applanata orally once daily for 2 days, then 2.2 grams daily thereafter until outbreak resolution, decreases the time to outbreak resolution by 6 days when compared with previous outbreaks (91434).
Gulf war syndrome. It is unclear if oral reishi mushroom is beneficial for Gulf war syndrome. Details: A very small exploratory clinical trial in adults with Gulf war syndrome shows that taking reishi mushroom extract (JHS Natural Products, Mushroom Science) 1600 mg in two divided doses daily for 30 days does not improve symptoms when compared with placebo. Also, symptoms modestly worsened after an additional 30 days of treatment at a dose of 3200 mg daily (108311).
Hepatitis B. One small clinical study suggests that a specific reishi mushroom extract may reduce hepatitis B activity and improve liver function. Details: Preliminary clinical research shows that taking a specific reishi mushroom extract (Ganopoly, Encore International Co.) 1800 mg orally three times daily for 12 weeks reduces levels of hepatitis B viral DNA and hepatitis B surface antigen, which are markers of hepatitis B activity, and normalizes aminotransferase levels in a greater percentage of patients when compared with placebo (70799).
Herpes labialis (cold sores). Oral reishi mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in adults with recurrent herpes labialis shows that taking 4.4 grams of a mixture of hot water extracts of reishi mushroom, terminalia, Job's tears, Wisteria floribunda, Trapa natans, and Elfvingia applanata orally once daily for 2 days, then 2.2 grams daily thereafter until outbreak resolution, decreases the time to outbreak resolution by almost 4 days when compared with previous outbreaks (91434).
Herpes zoster (shingles). Although there has been interest in using oral reishi mushroom for herpes zoster, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Human papillomavirus (HPV). Oral reishi mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research in patients with oral HPV shows that taking a combination of reishi and coriolus mushroom powders, 400 mg orally daily for 2 months, clears HPV in 88% of patients when compared with baseline (91433). The validity of this finding is limited by the lack of a comparator group.
Hypertension. Limited research suggests that oral reishi mushroom may be beneficial in some types of hypertension. Details: Preliminary clinical research shows that taking reishi mushroom extract 1440 mg daily for 12 weeks does not lower blood pressure in patients with hypertension (70776). However, in other clinical research, taking reishi mushroom extract 330-1440 mg daily for 1-6 months reduces blood pressure in patients with stage II or essential hypertension, but not in those with mild hypertension or diabetes (70786,70802,91435).
Influenza. Although there has been interest in using reishi mushroom for influenza, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Insomnia. Although there has been interest in using reishi mushroom for insomnia, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Lung cancer. Small clinical studies suggest that oral reishi mushroom does not reduce the size of lung tumors. Details: A meta-analysis of preliminary clinical research shows that taking reishi mushroom does not reduce the size of lung tumors. However, it may stimulate immune function and improve quality of life in lung cancer patients when compared with control (70779).
Peptic ulcers. Although there has been interest in using oral reishi mushroom for peptic ulcers, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose.
Rheumatoid arthritis (RA). Oral reishi mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with active RA who are taking disease-modifying antirheumatic drugs shows that taking reishi mushroom extract 4 grams in combination with San Miao San (containing 2.4 grams each of atractylodes, phellodendron, and Achyranthes bidentata) daily for 24 weeks does not increase the percentage of patients achieving a 20% response based on the American College of Rheumatology (ACR) criteria or modify blood markers of disease and inflammation when compared with placebo (70767).
Stress. Although there has been interest in using oral reishi mushroom for stress, there is insufficient reliable information about the clinical effects of reishi mushroom for this purpose. More evidence is needed to rate reishi mushroom for these uses.

SHIITAKE MUSHROOM (Shiitake (Lentinus edodes) fruiting body powder)

Dental Plaque. A solution containing an extract of shiitake mushroom is less effective than fluoride mouthwash for reducing dental plaque. Details: Clinical research shows that rinsing the mouth with a solution containing shiitake mushroom extract does not reduce dental plaque when compared with placebo and appears to be less effective than fluoride mouth rinse (Meridol) (94250).

Aging. Although there has been interest in using oral shiitake mushroom for aging, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Atherosclerosis. Although there has been interest in using oral shiitake mushroom for atherosclerosis, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Breast cancer. Although there has been interest in using oral shiitake mushroom for breast cancer, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Cancer. It is unclear if oral shiitake mushroom is beneficial in patients with cancer. Details: Although some small clinical studies in patients with gastric or colon cancer have found that patients taking the shiitake mushroom extract AHCC 3-6 grams daily have better survival rates and quality of life when compared with historical population data, other observational research has not found a benefit for patients with head, neck, lung, or breast cancer when compared with baseline (30421,30425,30454). The validity of these studies is limited by lack of a comparator group.
Chemotherapy-induced anemia. It is unclear if oral shiitake mushroom is beneficial in patients with chemotherapy-induced anemia. Details: A small clinical study in adults receiving chemotherapy for pancreatic cancer shows that taking the shiitake mushroom extract AHCC 6 grams daily for 8-12 weeks does not reduce the rate of grade 2 to 3 anemia when compared with placebo (110131).
Chemotherapy-induced leukopenia. It is unclear if oral shiitake mushroom is beneficial in patients with chemotherapy-induced leukopenia. Details: Preliminary clinical research in patients with breast cancer receiving chemotherapy shows that taking the shiitake mushroom extract AHCC significantly reduces chemotherapy-related neutrophil events and lipid abnormalities when compared with standard care (94829).Observational research in patients with resectable pancreatic ductal adenocarcinoma has found that taking this product orally 3 grams daily throughout 2 cycles of neoadjuvant gemcitabine improves the neutrophil-to-lymphocyte ratio and nutritional scores when compared with standard of care (106783). In contrast, other clinical research in patients with pancreatic or biliary tract cancer receiving gemcitabine chemotherapy shows that taking AHCC 6 grams daily for two months does not seem to affect neutropenia, thrombocytopenia, or hepatic dysfunction when compared with standard of care. However, taking AHCC did reduce C-reactive protein and increase hemoglobin and albumin when compared to standard of care (30424).
Chemotherapy-induced nausea and vomiting (CINV). It is unclear if oral shiitake mushroom is beneficial in patients with CINV. Details: Preliminary clinical research in patients being treated for head and neck cancers shows that taking the shiitake mushroom extract AHCC 3 grams daily, beginning 3 days prior to chemotherapy and continuing until one week after chemotherapy, reduces gastric side effects and the need for antiemetic therapy when compared with baseline (30425). The validity of these findings is limited by the lack of a comparator group.
Chemotherapy-induced taste changes. It is unclear if oral shiitake mushroom is beneficial for the prevention of taste changes due to chemotherapy. Details: A small clinical study in adults receiving chemotherapy for pancreatic cancer shows that taking the shiitake mushroom extract AHCC 6 grams daily for 8-12 weeks reduces the rate of patient-reported taste disorders by 27% when compared with placebo (110131). Although patients in the AHCC group had modest improvements in some nutritional parameters when compared with the placebo group, it is unclear if any changes would be considered clinically significant.
Common cold. Although there has been interest in using oral shiitake mushroom for the common cold, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Coronavirus disease 2019 (COVID-19). Although there has been interest in using oral shiitake mushroom for COVID-19, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Diabetes. Although there has been interest in using oral shiitake mushroom for diabetes, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Genital herpes. Although there has been interest in using oral shiitake mushroom for genital herpes, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Hepatitis C. It is unclear if oral shiitake mushroom is beneficial in patients with hepatitis C. Details: Preliminary clinical research in adults with chronic hepatitis C shows that taking the shiitake mushroom extract AHCC 6 grams daily for 6 months does not significantly reduce alanine aminotransferase (ALT) or hepatitis C virus RNA levels when compared with placebo (30419).
HIV/AIDS. Although there has been interest in using oral shiitake mushroom for HIV/AIDS, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Human papillomavirus (HPV). It is unclear if oral shiitake mushroom is beneficial in patients with HPV. Details: A small clinical study in adult females with persistent high-risk HPV shows that taking the shiitake mushroom extract AHCC 3 grams daily leads to clearance of HPV RNA and DNA in 64% of patients after 6 months of treatment, compared to 11% of patients taking placebo (110129). The validity of these findings is limited by lack of statistical comparison between groups.
Hypercholesterolemia. It is unclear whether oral shiitake mushroom is beneficial for lowering blood lipid levels. Details: Clinical research in adults with borderline high levels of cholesterol or triglycerides shows that consuming bars providing shiitake mushroom for 66 days modestly reduces triglyceride levels, but does not affect levels of low-density lipoprotein (LDL) cholesterol or high-density lipoprotein (HDL) cholesterol, when compared with placebo bars. Each bar provided dried shiitake mushroom 3.5 grams daily and the number of bars consumed daily was based on body mass index (108300). The effect of shiitake mushroom in patients with hypercholesterolemia, specifically, is unclear due to the heterogenous patient population.
Hypertension. Although there has been interest in using oral shiitake mushroom for hypertension, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Impaired glucose tolerance (prediabetes). Oral shiitake mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in adults with prediabetes shows that taking freeze-dried shiitake mushroom 0.96 grams in combination with chokeberry 1.36 grams, Panax ginseng 1.64 grams, and nattokinase 0.8 grams (Chakreis, YD Nutraceuticals Ltd.) twice daily for 12 weeks does not affect glycated hemoglobin, fasting blood glucose, or oral glucose tolerance test results when compared with placebo. However, there were some modest beneficial effects on insulin resistance and fasting insulin and liver transaminase levels (108301).
Influenza. Although there has been interest in using oral shiitake mushroom for influenza, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Liver cancer. Small, low-quality clinical studies suggest that oral shiitake mushroom extract may improve overall survival in patients with liver cancer. Details: Preliminary clinical research in patients with advanced hepatic cancer shows that taking the shiitake mushroom extract AHCC orally 6 grams daily for a median of 3.5 months along with supportive care increases the median survival time by 2 months when compared with placebo. Taking AHCC also improved quality of life scores when compared with placebo (30359). Population research in patients with hepatocellular carcinoma has also found that taking AHCC 3 grams daily for up to 9 years after surgical resection reduces tumor recurrence and mortality by 48% and 56%, respectively, when compared with control (30353). In another small, open label clinical study of adults with advanced hepatocellular carcinoma, tumor recurrence occurred in 52% of patients who took AHCC 1 gram three times daily for 2 years after surgical resection (110130). The interpretation of these results is limited by the lack of a control group.
Obesity. Although there has been interest in using oral shiitake mushroom for obesity, there is insufficient reliable information about the clinical effects of shiitake mushroom for this purpose.
Prostate cancer. It is unclear whether shiitake mushroom has a role in preventing disease progression. Details: Preliminary clinical research shows that taking shiitake mushroom extract does not prevent disease progression, as determined by prostate-specific antigen (PSA) levels, when compared with baseline (10451). More evidence is needed to rate shiitake mushroom for these uses.

TURKEY TAIL MUSHROOM (Coriolus (Coriolus versicolor) fruiting body extract)

POSSIBLY EFFECTIVE

Cancer. Taking PSK, a constituent of turkey tail mushroom, as an adjunct to standard cancer therapy may improve response rates and survival in some patients with cancer. Very limited data suggests that whole turkey tail mushroom is not beneficial. Details: The PSK constituent of turkey tail mushroom has been used as an adjunct to standard cancer therapy in Japan for several decades, in doses ranging from 1 to 3.6 grams daily (94076). It has been used in a dose of 3 grams daily for 24-36 months for breast (1648,1650,1654,1656), colorectal (1657,1660,70165,70167,70168,70171,70173,70174,70176,70190)(94076), esophageal (1649), gastric (1640,1651,1652,1657,1658,1659,1660,70161,70170,70175)(70179,70181,70183,70186,70189,70191,70194,70198), hepatic (1655,70188), and lung cancers (1653,70180,70184), as well as for leukemia (70200,70206). It has also been used in a dose of 1 gram daily for up to 72 months for colorectal cancer (94076), 1 gram three times daily for 1 month for nasopharyngeal cancer (1661,70195), and 2 grams/m2 per day in 3 divided doses, rotating in cycles with chemotherapy, for gastric cancer (1659,70194,70195). A meta-analysis of 13 clinical trials including over 2500 patients with esophageal, gastric, colon, rectal, breast, or nasopharyngeal cancer, shows that taking PSK in addition to conventional therapy reduces 5-year mortality by 9% when compared with conventional therapy alone. When individual cancer types are considered, the benefit of PSK is most evident in patients with breast, gastric, colon, or rectal cancer (94076). Another meta-analysis of 14 clinical trials shows that taking PSK, polysaccharide peptide (PSP), or turkey tail mushroom in combination with chemotherapy is associated with a 17% lower risk of mortality in some, but not all, types of cancer when compared with chemotherapy alone. However, overall there was no difference in relapse-free survival or total clinical efficacy, defined as complete responses plus partial responses (102915). The reliability and relevance of these meta-analyses is unclear since the trials looked at several different types of cancer, used varying doses and durations of therapy with different turkey tail mushroom extracts, and were all conducted in China or other Asian countries. Research on the use of whole turkey tail mushroom rather than the constituent PSK for treating cancer is limited. A small clinical study in 15 patients with inoperable hepatocellular carcinoma shows that taking turkey tail mushroom 2.4 grams daily for 6-12 weeks does not improve time to progression, progression-free survival, overall survival, or quality of life when compared with placebo (96568). However, this study was likely underpowered to detect any differences.

Cervical dysplasia. Intravaginal turkey tail mushroom has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A specific vaginal gel (Papilocare, Procare Health) containing turkey tail mushroom, neem, carboxymethyl-beta-glucan, hyaluronic acid, gotu kola, aloe, and alpha-glucan oligosaccharide has been examined in preliminary clinical and observational research in patients with human papillomavirus (HPV)-related cervical lesions. One clinical study shows that topical application for 6 months is associated with a normal Pap smear in 85% of patients, compared with 65% of those receiving only regular monitoring. Benefits were greatest in high-risk patients (108305). In patients over 40 years of age, treatment with this gel resulted in a normal Pap smear in 92% of patients, compared with 50% of those receiving only regular monitoring (111905). Both studies also showed improvements in cervical re-epithelization and HPV clearance (108305,111905). Observational research has also been conducted. One observational study in patients with high-risk HPV infection has found that using this same product is associated with 4.8-, 2.3-, and 5.1-fold increased odds of HPV DNA clearance, remission at colposcopy, and remission with cytology at 6 months, respectively, when compared with untreated patients (108306). In another observational study, using this product for 6 or 12 months is associated with repair of cervical low-grade lesions and a normalized cytology and colposcopy in about 75% of patients. HPV clearance was achieved in 71.6% of patients (111904). Doses of gel administration have varied. The gel is usually applied once daily for 21 days, followed by 7 days with no treatment, and then alternate days for up to 2-12 months (108305,108306,111904,111905). It is occasionally applied once daily for 21 days, followed by 7 days with no treatment, repeated for 3 months, and then alternated days for 3 months (108305).
Chronic fatigue syndrome (CFS). Although there has been interest in using oral turkey tail mushroom for CFS, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose.
Genital herpes. Although there has been interest in using oral turkey tail mushroom for genital herpes, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose.
Hepatitis. Although there has been interest in using oral turkey tail mushroom for hepatitis, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose.
Muscle strength. Although there has been interest in using oral turkey tail mushroom for muscle strength, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose.
Tinea corporis. Although there has been interest in using oral turkey tail mushroom for tinea corporis, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose.
Upper respiratory tract infection (URTI). Although there has been interest in using oral turkey tail mushroom for URTI, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose.
Urinary tract infections (UTIs). Although there has been interest in using oral turkey tail mushroom for UTIs, there is insufficient reliable information about the clinical effects of turkey tail mushroom for this purpose. More evidence is needed to rate turkey tail mushroom for these uses.

VITAMIN C

EFFECTIVE

Vitamin C deficiency. Oral or intramuscular vitamin C is effective for preventing or treating vitamin C deficiency. Details: Administering vitamin C orally or intramuscularly prevents and treats vitamin C deficiency, including scurvy. Vitamin C administration can reverse complications of scurvy within 2 days to 3 weeks (4844). In newborns with transient tyrosinemia due to vitamin C deficiency, oral or intramuscular vitamin C can correct this condition (15).

POSSIBLY EFFECTIVE

Anemia of chronic disease. Oral vitamin C seems to improve markers of anemia in patients on hemodialysis. Details: Meta-analyses of clinical research in hemodialysis patients with anemia shows that treatment with vitamin C 200-300 mg three times weekly for 3-6 months increases hemoglobin levels by approximately 0.9 grams/dL, increases transferrin saturation by about 8%, and decreases the required recombinant human erythropoietin dose by 17 U/kg weekly when compared with standard care (83447,83475).
Atrial fibrillation. Oral and intravenous vitamin C seems to help prevent atrial fibrillation after cardiac surgeries. Details: Meta-analyses of clinical research show that taking vitamin C prior to and after cardiac surgery reduces the risk of postoperative atrial fibrillation by 27% to 53%. Most studies administered vitamin C at doses of 1-2 grams orally daily for 1-3 days prior to cardiac surgery, followed by 1-2 grams in two divided doses daily for 4-5 days after cardiac surgery. Some studies provided vitamin C intravenously at similar doses, but oral vitamin C seems to be more effective (91233,96703,96705). Despite these findings, a meta-analysis of clinical research conducted only in the U.S. does not support the benefit of vitamin C for reducing postoperative atrial fibrillation (96703). These differences may be related to lifestyle factors such as nutrition, as well as differences in hospital treatments. Vitamin C has also been studied in combination with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) with evidence of benefit (90701).
Bowel preparation. Powdered vitamin C is approved for use as part of a polyethylene glycol-based bowel preparation for colonoscopy. Details: Clinical research shows that treatment with 2 liters of oral solution containing polyethylene glycol (PEG) plus vitamin C achieves a similar quality of bowel cleansing as treatment with 4 liters of PEG when administered on the evening prior to colonoscopy or when administered in a split-dose regimen. Patients given 2 liters of PEG plus vitamin C solution also have better adherence and experience fewer adverse events, such as nausea, vomiting, or abdominal bloating, compared to patients treated with 4 liters of PEG solution without vitamin C (90413,90415,90420,90424,90428). This treatment also appears to be effective and tolerable in elderly patients aged 60-79 years, including those with poor bowel habits and a high number of comorbidities (108085). Other clinical research in older adults undergoing bowel preparation for colonoscopy also shows that taking 1 liter of PEG plus vitamin C (CleanViewAL, Taejoon Pharm) results in similar quality of bowel cleansing overall and per segment with similar tolerability and adverse effects as sodium picosulfate 170 mL plus magnesium citrate or oral sulfate solution alone (111297,112476). The most common PEG plus vitamin C preparation used in clinical research is MoviPrep (Norgine BV), which contains macrogol 3350 100 grams, sodium sulfate 7.5 grams, sodium chloride 2.7 grams, potassium chloride 1 gram, vitamin C 4.7 grams, and sodium ascorbate 5.9 grams per liter of solution (90413,90415,90424). In the U.S., MoviPrep is approved by the Food and Drug Administration (FDA) for bowel preparation prior to a colonoscopy.
Cataracts. Dietary and supplemental intake of vitamin C may reduce the risk of developing cataracts. Details: Population research suggests that people with the highest total intake of vitamin C have about a 19% reduced risk of developing cataracts when compared with those with the lowest total intake, with the most benefit observed for nuclear cataracts (96711). Additionally, another observational study shows that higher supplemental intake of vitamin C over 10 years is associated with a 60% reduction in the incidence of nuclear and cortical cataracts (4208). Other population research suggests that individuals with the highest blood levels of vitamin C have a 33% lower odds of developing age-related cataract, but any benefit is limited to Asian populations (90944). An umbrella review of meta-analyses also shows that dietary intake of vitamin C is associated with a 27% lower odds of cataract development (112095). However, a prospective clinical study shows that a combination of vitamin C, vitamin E, and beta-carotene does not prevent age-related loss of vision from cataracts in well-nourished people with an average supplementation duration of 6.3 years (7304).
Common cold. Oral high-dose vitamin C might modestly shorten and reduce cold symptoms; however, taking vitamin C prophylactically does not seem to prevent the development of a cold. Details: There is substantial controversy about the effectiveness of vitamin C for treating the common cold (1969,1989,7100,9835,9836). The majority of evidence shows that taking high doses of vitamin C orally might decrease the duration of cold symptoms by 1-1.5 days in some patients (1966,1967,1968,1987,6458,7102,9832,83487). However, other studies have found no effect with doses up to 3 grams daily (9833). A meta-analysis of clinical research in healthy children and adults shows that taking vitamin C 1-4 grams daily for one week to 5 months reduces cold severity by 13%, limits absences from daily activities, and improves the duration of severe symptoms, but does not reduce the duration of mild symptoms, when compared with placebo (113665). Vitamin C has also been investigated for preventing the common cold. A meta-analysis of clinical research suggests that vitamin C supplementation decreases the incidence of cold in individuals exposed to physical stress, but not in the general population (83487). Other research suggests vitamin C may be more effective for treating cold symptoms in children than in adults. Also, there may be a dose-dependent response; doses of at least 2 grams daily seem to work better than 1 gram doses (9834). Taking vitamin C supplements prophylactically does not decrease the risk of catching a cold (1966,1967,1968,1987,3042,6458,7101,9832). Dietary intake of vitamin C also does not seem to affect the risk of getting a cold (10780).
Complex regional pain syndrome. Most research shows that taking oral vitamin C after a wrist or distal radius fracture or after orthopedic surgery seems to reduce the risk of developing complex regional pain. Details: Although some research has found no benefit in patients with distal radius (i.e. wrist) fractures (90411,96702), most clinical research shows that taking vitamin C 500 mg daily, and possibly doses of up to 1500 mg daily, for 45-50 days beginning immediately after fracture can reduce the risk of developing complex regional pain syndrome (2045,16302,96700,96706). Reasons for discrepancies are unclear but might relate to differences in diagnostic criteria for complex regional pain syndrome (96702). Research in patients undergoing orthopedic surgery has also shown benefit with the use of vitamin C for the prevention of complex regional pain syndrome (90422,108076,108087). One meta-analysis of clinical research in patients undergoing wrist, foot, or ankle surgery shows that taking vitamin C 500-1000 mg for 42-50 days following surgery reduces the rate of complex regional pain syndrome, and may improve pain following ankle or foot surgery, when compared with placebo (108076). The validity of these findings is limited by the high heterogeneity of included trials. Another meta-analysis of clinical research in patients undergoing orthopedic surgery (i.e. wrist, knee, ankle, foot, lumbar, rotator cuff) suggests that oral and intravenous vitamin C may have similar effectiveness; however, this evidence is low quality (108087).
Exercise-induced respiratory infections. High-dose oral vitamin C seems to reduce the risk of respiratory infections associated with strenuous exercise. Details: Some preliminary clinical research suggests that prophylactic use of vitamin C in doses of 600 mg to 1 gram daily for 3-8 weeks before heavy physical exercise, such as a marathon, might prevent upper respiratory infections that sometimes follow heavy exercise (9831,83370). More recently, high doses of vitamin C have been studied. A large clinical study in army recruits undergoing basic military training shows that taking vitamin C 6 grams daily for one month reduces the odds of getting a cold by 20% when compared with placebo (102975).
Hypercholesterolemia. Oral vitamin C seems to reduce lipid levels in patients with hypercholesterolemia. Details: A meta-analysis of clinical research in patients with hypercholesterolemia shows that taking vitamin C 500 mg daily for at least 4 weeks reduces low-density lipoprotein (LDL) cholesterol by about 8 mg/dL and reduces triglycerides by about 20 mg/dL when compared with control (83445).
Hypertension. Oral vitamin C seems to modestly reduce blood pressure in patients with hypertension, but some evidence is conflicting. Details: Vitamin C seems to modestly reduce systolic blood pressure (SBP), without meaningful effects on diastolic blood pressure (DBP) (2044,9822,13162,83483,102974). A meta-analysis of 13 clinical trials in patients with hypertension, with or without other comorbidities, shows that taking a median dose of vitamin C 500 mg daily for 8 weeks reduces SBP but not DBP by about 5 mmHg. Some of the studies used vitamin C in combination with other supplements, such as vitamin E and magnesium. When studies assessing vitamin C alone were analyzed, the magnitude of reduction in SBP decreased (83483). A newer meta-analysis of small clinical studies in patients with essential hypertension shows that taking vitamin C 200 mg or more daily reduces SBP by about 4 mmHg and DBP by about 2 mmHg (102974). However, this newer analysis omitted numerous relevant studies and included studies with normotensive patients and those without an adequate control, limiting the validity of its findings. In contrast, a network meta-analysis of small, low-quality clinical studies comparing five different vitamins in adults with essential hypertension shows that vitamin C does not reduce SBP, DBP, mean 24-hour SBP, mean 24-hour DBP, or heart rate when compared with placebo and when indirectly compared with vitamin B2, vitamin D, vitamin E, and folic acid. However, the included studies were of low quality and high heterogeneity, particularly in dosing, limiting the validity of the results (113668).
Laser skin resurfacing. Topical vitamin C seems to reduce erythema occurring after cosmetic laser skin resurfacing procedures intended to reduce scars and wrinkles. Details: There is some evidence that an aqueous formulation of topical vitamin C can decrease the degree and duration of erythema following cutaneous carbon dioxide laser resurfacing for scar and wrinkle removal (1959).
Lead toxicity. Dietary vitamin C seems to lower concentrations of lead in the blood. Details: Observational research has found that consuming more vitamin C from dietary sources is associated with lower blood concentrations of lead. People who consumed at least 340 mg of vitamin C daily as part of the diet had lower blood lead levels than those who consumed less than 100 mg vitamin C daily (3097,3098,3099).
Nitrate tolerance. Oral vitamin C might prevent nitrate tolerance in some patients. Details: Small clinical studies show that taking vitamin C orally seems to prevent the development of nitrate tolerance in patients taking sublingual nitroglycerin. There is some evidence that short-term vitamin C supplementation can prevent tolerance to the vasodilatory effects of nitrates (1441,1961).
Postoperative pain. Oral or intravenous vitamin C might prevent acute postoperative pain following certain surgeries. It is unclear if vitamin C reduces chronic postoperative pain. Details: A meta-analysis of 7 small clinical studies in adults undergoing elective surgery shows that receiving perioperative vitamin C, either as 1 gram orally, 2-3 grams intravenously, or 50 mg/kg intravenously, modestly reduces acute pain and opioid requirements for up to 24 hours when compared with control (105457). Most surgeries were laparoscopic and included cholecystectomy, colectomy, hysterectomy; two non-laparoscopic surgeries included uvulopalatopharyngoplasty with tonsillectomy and major abdominal surgery (90418,99840,105457). A meta-analysis of clinical trials in adults undergoing noncardiac surgery (i.e., orthopedic, abdominal, gynecologic, kidney transplantation) shows that administering perioperative vitamin C, either orally or intravenously, reduces postoperative intravenous morphine requirements at 2, 24, and 48 hours after surgery and improves pain scores at 2, 6, and 24 hours after surgery when compared with placebo. The dose of vitamin C did not appear to impact outcomes. However, when only laparoscopic surgeries are included, perioperative vitamin C does not improve pain or morphine use when compared with placebo (108087). A moderate-sized clinical study in adults undergoing transurethral resection of a bladder tumor under general anesthesia shows that administering intravenous vitamin C 1 gram after induction of anesthesia reduces the incidence and severity of catheter-related bladder discomfort immediately after surgery and at 1 and 2 hours postoperatively, but not 6 hours, when compared with placebo. However, vitamin C does not reduce postoperative pain scores or analgesic requirements when compared with placebo (111645). For dental surgery, a small observational study in adults undergoing surgery for wisdom tooth extraction shows that taking vitamin C 500 mg three times daily for 7 days in addition to standard treatment reduces pain 24, 48, and 72 hours after surgery when compared with control (113664). Further research is needed to determine the effects of vitamin C for acute postoperative pain. Vitamin C has also been evaluated for reducing chronic pain after surgery. Clinical research in patients undergoing surgery for foot or ankle trauma shows that taking vitamin C 500 mg orally twice daily postoperatively for 6 weeks reduces pain scores when compared with placebo at 2 weeks and 6 weeks. The mean total amount of diclofenac used for pain relief over the 6-week period is also reduced, from 5.7 grams with placebo to 3.4 grams with vitamin C (102131).
Wrinkled skin. Topical vitamin C might reduce the appearance of existing wrinkles. Details: Topical preparations containing vitamin C seem to improve the appearance of wrinkled skin. Some evidence shows that vitamin C 3% applied for 12 weeks might reduce facial wrinkles (14008). A small clinical study shows that applying a dissolving microneedle patch containing vitamin C 5.6% every 4 days for 12 weeks to crow's feet on one side of the face reduces wrinkles when compared to control treatment applied on the other side of the face (98780). Other clinical research in females aged 30-60 years shows that applying an oil-soluble cream containing the vitamin C derivative tetra-isopalmitoyl ascorbic acid 1%, 2%, or 3% to the periorbital area twice daily for 8 weeks reduces visual wrinkle grading when compared with placebo. A dose analysis shows greater improvements in wrinkle parameters, average wrinkle depth, and mean depth with the lower concentration, while greater improvements in maximum roughness and maximum depth are observed with the higher concentration (108072). This study only included individuals defined as having Fitzpatrick skin type III or IV; it effects on other skin types is unclear. Preparations containing vitamin C in combination with other ingredients have also been investigated. A small low-quality trial in females with moderately photodamaged and hyperpigmented facial skin shows that applying a moisturizer with vitamin C 30%, vitamin E, and coenzyme Q10 once daily in the morning, along with applying retinol 0.5% once daily or once every other day for 12 weeks, seems to improve skin tone, photodamage, and wrinkles when compared to baseline (99085). In another small trial, a topical preparation containing vitamin C 10% as L-ascorbic acid along with acetyl tyrosine, zinc sulfate, sodium hyaluronate, and bioflavonoids (Cellex-C High Potency Serum) applied to photo-aged facial skin for 3 months improves fine and coarse wrinkling, yellowing and sallowness, roughness, and skin tone when compared with placebo (6155). It is unclear if the beneficial effects of these products are due to vitamin C, other ingredients, or the combination.

Acute bronchitis. Oral vitamin C doesn't seem to improve symptoms of acute bronchitis. Details: A clinical study in adults with acute bronchitis shows that taking vitamin C orally 500 mg on day 1, then 250 mg on days 2 through 5 (similar to an azithromycin regimen) doesn't seem to have any effect on quality of life or bronchitis duration when compared with azithromycin (9827).
Asthma. Oral vitamin C doesn't seem to prevent asthma or improve lung function. Details: Although some observational research has found that some patients with asthma might have lower serum vitamin C levels (5873), other observational research found that increased dietary vitamin C intake is not associated with a reduced risk of asthma or improved lung function (15006,34567). In addition, clinical research shows that supplemental intake of vitamin C does not reduce asthma symptoms, improve lung function, or reduce the use of inhaled steroids in asthma patients (90409).
Atherosclerosis. Oral vitamin C does not seem to reduce the progression of atherosclerosis. Details: A clinical study shows that taking a specific combination product containing slow-release vitamin C 250 mg and vitamin E 136 IU (CellaVie, Ferrosan A/S) twice daily modestly slows the 3-year progression of atherosclerosis of the carotid artery in males, but not females. This result persisted at a 6-year follow-up of this study (1918,10473). However, when this form of vitamin C is used alone, it does not slow the 3-year progression of atherosclerosis of the carotid artery (1918).
Bladder cancer. Oral vitamin C does not reduce the risk of bladder cancer or mortality from bladder cancer. Details: Epidemiological research has found that supplemental vitamin C intake is not associated with mortality rate in patients with bladder cancer (9839). A secondary analysis of a large clinical trial, the Physicians' Health Study II, in healthy men aged at least 50 years also shows that taking vitamin C 500 mg daily alone or with vitamin E 400 IU daily for up to 10 years does not reduce the risk of developing bladder cancer or bladder cancer-related deaths when compared with placebo (90097).
Cardiovascular disease (CVD). Oral vitamin C does not seem to be beneficial for either primary or secondary CVD prevention. Details: Vitamin C does not seem to be beneficial for primary prevention of CVD. Some population research has found that higher supplemental vitamin C or dietary vitamin C has been associated with a reduced risk of developing CVD (10358,14108,109779), while other observational research has found no benefit (34566,10358,14108). However, meta-analyses of clinical research in healthy patients show that vitamin C supplementation does not prevent CVD or coronary heart disease when compared with control (97308,104025). In 2004, the American Heart Association stated that current evidence does not justify use of antioxidants such as vitamin C for reducing the risk of CVD (12142). Evidence is also negative for secondary prevention in people with coronary heart disease. Population studies have found that higher serum vitamin C was associated with no effect or decreased CVD mortality from CVD (3910,5878). A meta-analysis of two large clinical trials shows that vitamin C supplementation does not reduce CVD events or CVD mortality when compared with control (97308).
Colorectal cancer. Oral vitamin C does not seem to prevent colorectal cancer. Details: Population research has found that dietary vitamin C intake is not associated with a reduced risk of developing colon cancer. When total vitamin C intake from food and supplements is considered, there is a modest association (34600). However, most clinical trials show that supplemental vitamin C, alone or along with other antioxidants, does not reduce the risk of colorectal cancer development, colorectal cancer or adenoma recurrence, or colorectal cancer-related mortality (34580,34581,34594,90097,90089,92903).
Fetal and premature infant mortality. Oral vitamin C does not seem to prevent neonatal death. Details: Meta-analyses of clinical research show that taking vitamin C alone or with other supplements does not reduce the risk of neonatal death (83472,96707).
Fractures. Oral vitamin C does not seem to improve fracture healing. Details: Clinical research shows that taking vitamin C 500 mg daily for 50 days following an acute distal radial fracture does not improve physical function, symptoms, or healing rates when compared with placebo (90411).
Helicobacter pylori. Oral vitamin C does not seem to improve eradication of H. pylori. Details: Most clinical research shows that treatment with vitamin C, alone or in combination with vitamin E, does not improve the eradication rate of H. pylori when taken with a standard eradication regimen when compared with the eradication regimen alone (83476,90094).
Hereditary motor and sensory neuropathy. Oral vitamin C does not seem to improve neuropathy in these patients. Details: In a meta-analysis of five studies in patients with Charcot-Marie-Tooth disease type 1A, taking vitamin C 1-4 grams orally daily for 1 year did not improve neuropathy when compared with placebo (99084). Continuing vitamin C 4 grams daily for 2 years also does not improve neuropathy in these patients (90419).
Interferon-related retinopathy. Oral vitamin C does not seem to improve retinopathy associated with interferon therapy. Details: A small clinical study in patients with chronic hepatitis C receiving interferon therapy shows that taking vitamin C 600 daily orally does not seem to reduce the risk of retinopathy from interferon therapy when compared with control (10355).
Leukemia. Oral vitamin C does not seem to reduce the risk of leukemia or mortality from leukemia. Details: A large clinical trial in men aged at least 50 years shows that taking vitamin C 500 mg daily, alone or along with vitamin E 400 IU daily, for up to 10 years does not reduce the risk of developing leukemia or leukemia-related deaths when compared with placebo (90097).
Low birth weight. Oral vitamin C does not seem to reduce the risk of infants being born with a low birth weight. Details: Meta-analyses of clinical research show that maternal use of oral vitamin C alone or with other supplements does not reduce the risk of giving birth to infants with low birth weight when compared with control (83450,83472).
Lung cancer. Oral vitamin C does not seem to reduce the risk of lung cancer. Details: Two meta-analyses of clinical research suggest that taking vitamin C, alone or in combination with vitamin E, does not reduce the incidence of lung cancer or lung cancer-related mortality (34528,34632). Also, a clinical study in females shows that taking supplemental vitamin C 500 mg daily, with or without vitamin E and beta carotene, is associated with an INCREASED risk of lung cancer when compared with placebo (34580). However, another large epidemiological cancer screening trial with a mean follow-up of over 12 years suggests that moderate dietary intake of vitamin C around 500 mg daily is protective against lung cancer, but higher doses of vitamin C might increase the risk of lung cancer (112096).
Melanoma. Oral vitamin C does not seem to reduce the risk of melanoma. Details: Clinical research shows that taking vitamin C 500 mg daily, alone or along with vitamin E 400 IU daily, for up to 10 years does not reduce the risk of developing melanoma or melanoma-related deaths when compared with placebo in men aged at least 50 years (90097).
Miscarriage. Oral vitamin C does not seem to reduce the risk of miscarriage. Details: A meta-analysis of clinical research shows that taking vitamin C alone or with other supplements does not reduce the risk of miscarriage when compared with control (94820).
Overall mortality. Oral vitamin C does not reduce overall mortality. Details: Although population research suggests that higher dietary intake and higher plasma vitamin C levels are associated with a reduced risk of mortality from all causes (3910,109779), vitamin C supplementation does not seem to affect overall mortality. Meta-analyses of clinical research show that taking vitamin C supplements does not reduce overall mortality when compared with control (34622,111641). Clinical studies of vitamin C used in combination with vitamin E, beta carotene, and/or selenium and zinc, also show no benefit for overall mortality (9817,14109).
Pancreatic cancer. Oral vitamin C does not seem to prevent pancreatic cancer. Details: Observational research has found that increased dietary vitamin C intake is associated with up to a 30% reduced risk of pancreatic cancer (99083,99086). However, clinical research shows that supplemental vitamin C 500 mg daily does not reduce the risk of pancreatic cancer in females (34580). Also, taking vitamin C in combination with beta-carotene plus vitamin E does not reduce the risk of pancreatic cancer (12185,34581).
Pre-eclampsia. Oral vitamin C does not seem to prevent pre-eclampsia. Details: Despite some early positive research in high-risk pregnancies, the majority of meta-analyses and clinical studies show that taking vitamin C alone or with vitamin E or other supplements does not reduce the risk of pre-eclampsia when compared with control. There is even some concern that vitamin C supplementation may increase the risk of gestational hypertension (3236,83450,83472,83474,96707).
Preterm labor. Oral vitamin C does not seem to prevent preterm labor. Details: Meta-analyses of clinical research show that taking vitamin C alone or with other supplements does not reduce the risk of preterm labor when compared with control (83450,83472,96707).
Prostate cancer. Oral vitamin C does not seem to prevent prostate cancer. Details: A large-scale clinical study (The SU.VI.MAX study) shows that a combination of vitamin C 120 mg, vitamin E (alpha-tocopherol) 30 mg, beta-carotene 6 mg, selenium 100 mcg, and zinc 20 mg, taken daily for an average of 8 years, does not reduce the risk of prostate cancer overall. However, it might reduce the risk of prostate cancer in those who have normal PSA levels. It does not seem to be beneficial for reducing the risk of prostate cancer in patients with PSA levels above 3 mcg/L (14135). Another large scale study (Physician's Health Study II) shows that taking vitamin C 500 mg daily for an average of 8 years does not significantly reduce the risk of prostate cancer when compared with placebo (16708). Similarly, results from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial seem to show that supplemental or dietary intake of vitamin C does not reduce the risk of prostate cancer when compared to individuals not taking vitamin C (14124).
Radiation dermatitis. Topical vitamin C does not seem to prevent radiation dermatitis in cancer patients. Details: A small clinical study shows that applying a 10% vitamin C solution does not appear to protect from radiation dermatitis when applied to the scalps of patients treated with radiation for intracranial tumors (789).
Small for gestational age (SGA). Oral vitamin C does not seem to reduce SGA. Details: Meta-analyses of clinical research show that taking vitamin C alone or with other supplements does not reduce the risk of small for gestational age birth when compared with control (83450,83472).
Stillbirth. Oral vitamin C does not seem to prevent stillbirth. Details: Meta-analyses of clinical research show that maternal use of vitamin C alone or with other supplements does not reduce the risk of stillbirth when compared with control (83472,96707).

LIKELY INEFFECTIVE

Coronavirus disease 2019 (COVID-19). Oral vitamin C, even at high doses, does not seem to speed recovery from COVID-19 in non-hospitalized patients. Most studies show that oral or intravenous vitamin C given to patients hospitalized with COVID-19 does not improve organ function or survival, but the evidence is conflicting. It is unclear whether vitamin C is beneficial for long COVID. Details: A clinical study in adult outpatients with confirmed COVID-19 shows that taking oral vitamin C (ascorbic acid) 8000 mg in 2-3 divided doses daily, alone or with zinc gluconate 50 mg daily, for 10 days does not reduce symptom severity when compared with standard care (104450). The study was terminated prior to complete enrollment due to futility and apparent lack of effect from vitamin C and/or zinc supplementation. Limitations of this study include a lack of placebo control and blinding. Additionally, this study has been criticized for methodologic concerns (106624). Another small clinical trial in adult outpatients with confirmed COVID-19 shows that taking vitamin C 1000 mg daily for 14 days does not improve symptoms or quality of life when compared with placebo (109462). Vitamin C has also been evaluated in patients hospitalized with COVID-19. A very large analysis of two multinational clinical studies in critical and non-critical adults hospitalized with COVID-19 shows that administering intravenous vitamin C 50 mg/kg every 6 hours for 96 hours does not improve organ support-free days or survival and has a high probability of futility and worsened outcomes when compared with placebo (113666). Individual prospective and retrospective studies in critically ill patients hospitalized with COVID-19 in various countries have found that administering vitamin C, either enterally as 500-1000 mg daily or intravenously as 8-24 grams daily or 50 mg/kg daily, does not significantly reduce in-hospital or short-term mortality, hospital length of stay, or end-organ failure when compared with control groups receiving standard care alone. Additionally, all but one study found no change in the need for mechanical ventilation (105458,105465,106937,106938,108075,108079,108081). However, a meta-analysis and some small individual studies have found that vitamin C is modestly beneficial for patients hospitalized with COVID-19. A meta-analysis of 10 clinical trials and 9 observational studies in patients hospitalized with COVID-19 shows that receiving oral or intravenous vitamin C daily reduces the odds of in-hospital mortality by 41% when compared with control. When only clinical trials were considered, the odds of in-hospital mortality were decreased by 56%; however, this reduction was only identified in studies using vitamin C 10 grams daily or less. Conversely, supplementation with vitamin C increased the length of intensive care unit (ICU) stay by nearly 2 days and did not impact length of hospital stay or reduce the need for mechanical ventilation, liver injury, or cardiac injury (109955). Additionally, a small study found a small improvement in survival when compared with standard care; however, the overall survival rate in this study was low (108075). Another clinical study in patients hospitalized in Turkey with COVID-19 shows that adding high-dose intravenous sodium ascorbate 50 mg/kg to a treatment regimen of hydroxychloroquine, azithromycin, and zinc may improve recovery time, with 57% and 39% of patients achieving total recovery at day 15 in the vitamin C and control groups, respectively (108071). However, the validity of this trial is limited due to unclear reporting. Additionally, these small studies were likely underpowered to detect differences between the vitamin C and control groups. Vitamin C has also been evaluated in combination with other ingredients in patients with long COVID. Preliminary clinical research in adults with long COVID and persistent fatigue shows that taking a specific combination product containing vitamin C 500 mg and L-arginine 1.66 grams (Bioarginina C, Farmacetici Damor) for 28 days increases 6-minute walk test distance by 10% and reduces self-reported fatigue when compared with placebo (110390). However, it is unclear whether these effects are due to vitamin C, L-arginine, or the combination.
Sepsis. Intravenous vitamin C, alone or in combination with thiamine and/or hydrocortisone, does not prevent organ failure, reduce intensive care or hospital length of stay, or reduce mortality in sepsis or septic shock. Details: Observational research suggests that patients with septic shock are more likely to have low plasma levels of vitamin C (100317). However, two randomized clinical trials in patients with sepsis show no benefit with intravenous vitamin C, with or without thiamine, for improving organ function and preventing organ failure when compared with control treatment (102130,104027). A clinical study in patients with septic shock shows that administering an intravenous bolus of vitamin C 1000 mg followed by a continuous infusion of 250 mg/hour for 96 hours, starting within 24 hours of vasopressor initiation, does not improve 28-day or intensive care unit (ICU) mortality when compared with placebo. A subgroup analysis shows that the addition of corticosteroids does not affect outcomes in either group (108078). This study may have been inadequately powered to detect a difference between groups. Also, a larger clinical trial in adults with sepsis receiving vasopressor therapy in the ICU shows that intravenous administration of vitamin C 50 mg/kg every 6 hours for up to 4 days increases the risk of death or persistent organ dysfunction at day 28 by 14% to 21% when compared with placebo. There were no differences in mortality at 6 months (109459,111643). Vitamin C has also been frequently studied in patients with sepsis and septic shock in a specific combination regimen (HAT therapy) which includes intravenous vitamin C 1.5-2 grams with hydrocortisone 50 mg every 6 hours and thiamine 200 mg every 12 hours. While some retrospective research has found HAT therapy to be beneficial in sepsis (100315,102980), high quality, prospective clinical research has not confirmed these findings (105447,106620,109956). Several meta-analyses of randomized controlled trials and small clinical studies in patients with sepsis or septic shock show that intravenous vitamin C, either alone, as a component of HAT therapy, or in combination with thiamine, does not reduce short- or long-term mortality, ICU or hospital length of stay, kidney injury, or duration of mechanical ventilation, but modestly improves duration of vasopressor use and procalcitonin clearance, when compared with placebo or standard care. These analyses also show mixed results with respect to improvement in sequential organ failure assessment (SOFA) scores within 72 hours (105447,106620,106935,108073,109460,111298,111300,111301,111642,112479). Most studies included in the analyses administered HAT therapy for 2-10 days and compared it with normal saline control or with hydrocortisone alone (102129,102998,104027,104028,104032,105446). Although some subgroup analyses suggests that intravenous vitamin C alone in patients with sepsis may improve short-term mortality (106620,111298), other meta-analyses have not shown this benefit in subgroup analyses (111300). In addition, meta-analyses have identified significant publication bias (111298,111300). Long-term follow up from a study in patients with sepsis-induced respiratory and/or cardiovascular dysfunction shows that receiving HAT therapy does not improve cognitive, psychological, or functional status after 6 months and, for some domains, HAT therapy was worse when compared with placebo (111299). Studies evaluating intravenous vitamin C, either alone, as a component of HAT therapy, or in combination with thiamine, in mixed critically ill populations have also shown mixed findings. Four meta-analyses of randomized controlled trials and observational studies show that intravenous vitamin C does not have a significant effect on the length of hospital stay, mortality at 1 month, ICU mortality, use of invasive ventilation, use of renal replacement therapy, organ function, or incidence of kidney injury when compared with placebo or standard care. The meta-analyses reach conflicting conclusions on whether intravenous vitamin C reduces the risk of in-hospital mortality, 30-day mortality, and the duration of ICU stay. When only data from low risk-of-bias clinical trials are considered, the effects of intravenous vitamin C on mortality at any point are no longer significant (106933,106934,109957,113663). However, a subgroup analysis in one of these analyses suggests that intravenous vitamin C as monotherapy, or in doses of at least 10 grams daily, may improve overall mortality (106934). Vitamin C also does not appear to benefit complications from sepsis, such as vasoplegic shock. A small clinical study in adults in the ICU with vasoplegic shock mostly secondary to sepsis and requiring moderate vasopressor support shows that administering intravenous vitamin C as sodium ascorbate 1.5 grams every 6 hours for 5 days or until cessation of vasoactive therapy does not reduce the duration of vasopressors, vasopressor dose, hospital or ICU length of stay, or mortality outcomes when compared with placebo (112475).

Atrophic acne scars. It is unclear if applying topical vitamin C after microblading improves atrophic acne scars. Details: A clinical study in adults with mild to severe atrophic acne scarring shows that applying a serum containing vitamin C 17% to the face after a once-monthly home microblade treatment for 4 months improves the appearance of acne scars at month 5 when compared with baseline (108086). Although this study enrolled a control group that used topical insulin in place of vitamin C, no between-group statistical comparisons were conducted, limiting the validity of this study.
Age-related macular degeneration (AMD). It is unclear if dietary vitamin C or oral vitamin C taken in combination with other ingredients prevents AMD. Details: An umbrella review of meta-analyses shows that increased dietary intake of vitamin C is associated with 21% higher odds of developing AMD (112095). A population study suggests that vitamin C intake is associated with increased odds of developing age-related maculopathy (9823). However, other population studies have found no association between dietary or supplemental vitamin C intake and the risk of developing AMD (14007,14257). When taken in combination with other ingredients, most clinical and population research shows that taking vitamin C 500 mg along with other antioxidants such as vitamin E 400 IU, beta-carotene 15 mg, and/or elemental zinc 80 mg reduces the risk of visual acuity loss by 23% to 27%, progression to advanced AMD at 5 years by 25% to 32%, and AMD overall (7303,7304,11326,14257,90069). The antioxidant plus zinc combination seems to reduce the risk of progression to advanced AMD in these patients more than taking the antioxidants without zinc (7303,90069). More evidence is needed to determine what role, if any, vitamin C intake has on the risk of developing AMD.
Aging skin. Topical vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Clinical research in females aged 30-65 years shows that applying a specific liquid (Antioxidant and Collagen Booster Serum, Max Biocare Pty Ltd.) containing vitamin C 20%, red raspberry leaf cell culture extract 0.0005%, and vitamin E 1% to the face nightly for 8 weeks, in addition to regular facial skin products, improves skin color, elasticity, radiance, smoothness, and appearance of wrinkles when compared with regular facial skin products alone (102355).
Albuminuria. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study shows that taking vitamin C 1250 mg plus vitamin E 680 IU daily for 4 weeks can reduce the excretion of albumin by about 19% when compared with placebo in patients with type 2 diabetes (10434).
Allergic rhinitis (hay fever). It is unclear if oral vitamin C is beneficial in patients with hay fever. Details: Epidemiological research has found that higher vitamin C plasma levels are not associated with a decreased risk of allergic rhinitis (15200). However, clinical research shows that some forms of vitamin C might help. In one small clinical study, intranasal vitamin C administered three times daily for 2 weeks reduces nasal secretions, nasal blockage, and edema in up to 74% of patients with perennial allergic rhinitis (15201). Another small clinical study in patients with seasonal allergic rhinitis shows that taking a single oral dose of vitamin C 2 grams reduces bronchial responsiveness to histamine at one hour after ingestion (15202). However, in another small study in patients with seasonal allergic rhinitis taking vitamin C orally in doses up to 4 grams daily for 3 days does not appear to suppress cutaneous or nasal response to histamine when compared to placebo (15203).
Alzheimer disease. It is unclear if dietary vitamin C helps to prevent this condition. Details: Most epidemiological research has found that dietary intake of vitamin C is associated with a 17% reduced risk of developing Alzheimer disease (4636,9824,10131,13165,90082).
Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease). It is unclear if oral vitamin C helps to prevent ALS. Details: Observational research has found that increased dietary or supplemental intake of vitamin C is not associated with risk of developing ALS (90412).
Anthracycline cardiotoxicity. Although there is interest in using oral vitamin C for anthracycline-induced cardiac toxicity, there is insufficient reliable information about the clinical effects of vitamin C for this condition.
Aspirin-associated gastric damage. It is unclear if oral vitamin C helps to prevent gastric damage caused by aspirin. Details: Some clinical research shows that vitamin C 480 mg might prevent gastric damage associated with taking aspirin 400 mg by decreasing blood loss and preventing decreased gastric blood flow (10357). However, a small clinical study in healthy patients shows that taking vitamin C 500 mg as ascorbic acid with aspirin 600 mg actually increases gastrointestinal permeability to a greater extent than either ingredient taken alone (98781).
Athletic performance. It is unclear if oral vitamin C improves athletic performance. Details: Although some small preliminary clinical studies suggest that vitamin C might improve certain biomarkers during exercise (82922), a meta-analysis of small clinical trials in older and younger adults shows that taking vitamin C 500-1000 mg daily, with or without vitamin E, does not improve endurance, lean mass, or muscle strength when compared with placebo (102973). A more recent, small clinical study in recreationally trained males shows that taking vitamin C 1000 mg and vitamin E (as alpha-tocopherol) 235 mg daily for 10 weeks while participating in a resistance training program does not improve measures of muscle strength when compared with placebo (109959).
Atopic disease. It is unclear if dietary vitamin C helps to prevent atopic disease. Details: Population research has found that higher intake of vitamin C is not associated with a reduced risk of eczema, wheeze, IgE-mediated food allergy, or allergic sensitization (90098).
Attention deficit-hyperactivity disorder (ADHD). Small clinical studies suggest that high-dose oral vitamin C may not improve symptoms in patients with ADHD. Details: Some research suggests that taking megadose vitamins, including vitamin C, does not improve ADHD symptoms (9957,9958,9959). However, other preliminary clinical research shows that taking 25 mg of vitamin C in combination with flaxseed oil providing alpha-linolenic acid 200 mg twice daily might improve measures of attention, impulsivity, restlessness, and self-control in children with ADHD when compared with baseline (14443). It is not clear if these effects are due to vitamin C, flaxseed oil, or the combination.
Autism spectrum disorder. It is unclear if oral vitamin C is beneficial in patients with autism spectrum disorder. Details: One small clinical study shows that taking vitamin C 8 grams per 70 kg daily for 10 weeks modestly reduces autism symptom severity in school children when compared with placebo (83604).
Bleeding. It is unclear if intravenous vitamin C can reduce bleeding after total abdominal hysterectomy. Details: A small clinical study in patients undergoing total abdominal hysterectomy shows that administration of intravenous vitamin C 1 gram the night before surgery and 1 gram during surgery reduces postoperative hemorrhage volume by around 40 mL when compared with placebo (109465).
Brain tumor. It is unclear if oral vitamin C helps to prevent brain tumors. Details: Population research has found that vitamin C intake is associated with a 14% reduced risk of glioma. This risk reduction was more prevalent in America compared to other geographic locations (98782).
Breast cancer. It is unclear if oral vitamin C helps to prevent breast cancer, its recurrence, or breast cancer-related mortality. Details: Some epidemiological research has found that dietary vitamin C is associated with a reduced risk of breast cancer (1444,10823,10824). However, other epidemiological research has found no association with dietary or supplemental vitamin C (10825,10826,108080). One cohort study found no association between breast cancer risk and total, dietary, or supplemental vitamin C, regardless of dose, treatment duration, or formulation (single ingredient or combination product). Additionally, hormone and menopausal status did not appear to impact risk. Vitamin C intake might be associated with a reduced risk in individuals with a family history of breast cancer in first-degree relatives (108080). In patients with breast cancer, supplemental or dietary intake of vitamin C might be associated with a reduced risk of mortality. A meta-analysis of results from population research shows that vitamin C supplementation following breast cancer diagnosis is associated with a 15% lower risk of breast cancer-related mortality when compared with no supplementation (90416). A large, observational study in patients with breast cancer undergoing radiation therapy has found that vitamin C supplementation does not reduce the risk of breast cancer recurrence over a period of 5 years when compared with no supplementation. Although the vitamin C group had notably less aggressive tumor types, recurrence-free survival was similar in both vitamin C and control groups (108082). The validity of these findings is limited due to unknown doses of vitamin C and the inclusion of various breast cancer subtypes.
Burns. Small studies suggest that intravenous vitamin C may modestly improve symptoms in patients with severe burns. Details: A small clinical study in patients with severe burns shows that administering vitamin C intravenously (IV) 66 mg/kg hourly over 24 hours, as part of fluid resuscitation using lactated ringer solution, reduces wound edema and the volume of fluid needed when compared with fluid resuscitation alone (83145). A retrospective review of adults hospitalized with severe burns has found that those who receive a continuous IV infusion of at least 10 grams of vitamin C within 2 days of admission have an in-hospital mortality rate of 46%, compared with 58% for those who do not receive vitamin C (102128).
Cancer. It is unclear if oral or intravenous vitamin C helps to prevent cancer or cancer-related mortality. Details: Some population research has found that DIETARY intake of vitamin C is linked with a lower risk of cancer and cancer-related mortality (3910,5878,10819,109779). However, clinical research shows that taking vitamin C SUPPLEMENTS does not reduce the risk for cancer (10819,14109,34580,90097). In people with cancer, although some clinical research has shown that taking high-dose vitamin C supplements can improve survival rates (9809,96704), other clinical research has not shown this benefit (4842,4843). In 2003, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that some scientific evidence suggests that antioxidant vitamins, such as vitamin C, may reduce the risk of certain forms of cancer. However, the FDA has determined that there is little scientific evidence supporting this claim (102334). Preliminary clinical research has also evaluated vitamin C supplements in patients with cancer. High-dose oral vitamin C, 10 grams daily, in patients with advanced cancer does not seem to improve survival or decrease disease progression (4842,4843,106617). However, preliminary clinical research suggests high doses of vitamin C, given intravenously, might have a beneficial effect on some outcomes, including survival rate in some patients with cancer (9809,96704,106617). However, there is no benefit to other patients studied in the case reports and this has not been tested in well-designed clinical trials (9809,96704).
Cardiac arrest. It is unclear if intravenous vitamin C is beneficial for patients after cardiac arrest. Details: A small clinical study conducted in Slovenia in adult survivors of out-of-hospital cardiac arrest shows that administering intravenous vitamin C 1.5 grams every 12 hours for 8 consecutive doses, with the first dose administered within 6 hours of resuscitation, in addition to standard care protects against arrhythmias and reduces the length of intensive care unit (ICU) stay when compared with placebo and standard care. However, intravenous vitamin C does not appear to protect against neurological or myocardial injury, reduce the need for mechanical ventilation, reduce the duration of hospital stay, or increase survival when compared with placebo (113667).
Carpal tunnel syndrome. Vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A clinical study in adults with mild to moderate carpal tunnel syndrome shows that taking a combination product containing vitamins C, E, B1, B2, B6, and B12, alpha-lipoic acid, acetyl-L-carnitine, phosphatidylserine, and turmeric twice daily for 60 days reduces symptom severity and pain but does not improve measures of hand and wrist function when compared with control (111702). The validity of these effects is limited by a lack of blinding. The study may also be inadequately powered to detect a difference between groups. Additionally, it is unclear if the effects are due to vitamin C, other ingredients, or the combination.
Cervical cancer. It is unclear if oral vitamin C helps to prevent cervical cancer. Details: Observational research has found that higher vitamin C intake is associated with a 33% to 42% reduced odds of cervical neoplasm. Increasing vitamin C intake by 50 mg daily is associated with an 8% reduced odds of cervical neoplasm (34609,98771).
Chronic fatigue syndrome (CFS). Although there is interest in using oral vitamin C for CFS, there is insufficient reliable information about the clinical effects of vitamin C for this condition.
Colistin-induced nephrotoxicity. It is unclear if intravenous vitamin C helps to prevent nephrotoxicity from colistin. Details: A small clinical study shows that intravenous administration of vitamin C 2 grams every 12 hours along with colistin for around 9-10 days does not prevent nephrotoxicity when compared with colistin therapy alone (99839). However, this study was limited by a lack of statistical power to detect differences between the study groups.
Contrast induced nephropathy. It is unclear if oral vitamin C helps to prevent contrast-induced nephropathy (CIN). Details: Some clinical research shows that taking vitamin C before and after coronary angiography reduces the risk of developing CIN by 33% to 55% when compared with placebo in patients with renal dysfunction (12234,90421). However, other clinical evidence published since 2012 suggests that vitamin C given orally and/or intravenously before and after angiography does not reduce the risk of CIN compared with control in high-risk patients with chronic renal insufficiency or diabetes (91232,91236,90410,90425). Reasons for the discrepancies are not entirely clear. However, it is possible that the lack of significant benefit from vitamin C in the latter studies results from the fact that incidences of CIN have become less common than in the past due to avoidance of dehydration, use of smaller catheters, and use of contrast agents with reduced nephrotoxicity (90429).
Coronary artery bypass graft (CABG) surgery. It is unclear if intravenous vitamin C helps to improve patient outcomes after CABG surgery. Details: A small clinical study shows that giving vitamin C 5 grams intravenously (IV) before anesthesia induction and 5 grams in the cardioplegia solution used during surgery shortens the length of stay in the intensive care unit (ICU) by about 8 hours (102127). However, some limited research suggests that IV vitamin C does not resolve cardiac surgery complications. A small clinical study in patients with vasoplegia after receiving CABG and other cardiac surgeries shows that receiving IV vitamin C 1.5 grams every 6 hours after being admitted to the ICU does not improve vasoplegia when compared with control (102981).
Delirium. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Observational research in adults with septic shock has found that receiving intravenous thiamine 400 mg daily with vitamin C 6 grams daily, both in divided doses, is not associated with reduced delirium when compared with control (103001).
Dental plaque. It is unclear if vitamin C in a chewing gum helps to reduce dental plaque formation. Details: A small clinical study in patients with calculus shows that chewing 10 pieces of gum, each containing 60 mg of vitamin C, daily for 3 months reduces the formation of dental calculus, visible plaque, and the number of bleeding sites when compared not chewing gum (83303). The validity of this finding is limited by a lack of placebo group.
Depression. It is unclear if oral vitamin C is beneficial for the treatment or prevention of depression. Details: A small clinical study in children and adolescents shows that taking vitamin C 500 mg orally twice daily in combination with fluoxetine 10-20 mg daily for 6 months reduces most symptoms of major depressive disorder when compared with taking fluoxetine alone (90404). However, a small clinical study in adults shows that taking vitamin C up to 1000 mg daily for 2 months does not improve the response rate or decrease symptoms of depression in adults also taking citalopram when compared with citalopram alone (96708). Reasons for these conflicting results may relate to the age of the patients, study duration, or differences in antidepressant medication being taken. One clinical guideline also provisionally recommends against the use of oral vitamin C to treat patients with depression based on low-quality evidence (110318). Some research has also evaluated vitamin C intake for the prevention of depression. A secondary analysis of pre- and peri-menopausal adults enrolled in the Study of Women's Health Across the Nation (SWAN) program suggests that vitamin C intake is inversely associated with depressive symptoms. This association persisted regardless of age, race, physical activity, body mass index, antidepressant use or menopausal status (108083). The validity of these findings is limited due to the secondary nature of this study; additionally, follow-up time is unclear.
Diabetes. It is unclear if oral vitamin C prevents diabetes. Some low-quality research suggests that vitamin C might improve glycemic control in patients with diabetes. Details: Population research has not found a link between dietary vitamin C and the risk of developing type 2 diabetes (14004). However, low certainty clinical research has found some benefit of taking vitamin C supplements for glycemic control. Two meta-analyses of several small, heterogeneous clinical studies in patients with type 2 diabetes show that taking vitamin C 200-3000 mg daily for 2-48 weeks reduces fasting blood glucose by approximately 11 mg/dL (112478) and glycated hemoglobin (HbA1c) by an average of 0.5% when compared with placebo, standard treatment, or no treatment (105461,112478). Subgroup analyses suggest that durations of supplementation longer than 12 weeks show greater glycemic benefit, and although one meta-analysis suggests there is no dose-response relationship (105461), another meta-analysis suggests that doses of vitamin C 1000 mg and higher are most beneficial for improving glycemic indices (112478). Some research has evaluated the effects of vitamin C supplementation on the lipid profile in patients with diabetes, with mixed findings. One meta-analysis of 17 small clinical studies shows that taking vitamin C 200-3000 mg daily for 2 to 48 weeks improves levels of triglycerides and total cholesterol, but not low-density lipoprotein (LDL) or high-density lipoprotein (HDL) cholesterol. Subgroup analysis suggests that study durations of at least 12 weeks show greater benefit (106621). However, two other meta-analyses in patients with diabetes, one of 16 small heterogenous clinical studies and one of 11 small clinical studies, show no clinically important improvement in lipid levels after vitamin C supplementation (105461,105464).
Dry mouth. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear. Details: A small clinical trial in patients receiving radiotherapy for head and neck cancer shows that taking vitamin E 100 IU and vitamin C 500 mg twice daily for an average of 3 months improves dry mouth when compared to baseline (99080). The validity of these results is limited by the lack of comparison with a control group.
Endometrial cancer. Increased dietary vitamin C has been linked to reduced risk of endometrial cancer. Details: Population research has found that intake of vitamin C from dietary sources is associated with a slightly decreased risk of endometrial cancer when compared with control. However, this benefit is not observed when results from a prospective cohort study are assessed (34578).
Endometriosis. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear. Details: A small clinical study in patients with endometriosis and pelvic pain shows that taking vitamin C 1000 mg and vitamin E 800 IU daily for 8 weeks improves dysmenorrhea, dyspareunia, and chronic pelvic pain scores when compared with placebo. Vitamin C and vitamin E supplementation also reduces some biochemical markers of oxidative stress when compared with placebo (106622).
Endoscopy-associated adverse effects. It is unclear if a topical vitamin C spray reduces mucosal irritation in patients undergoing Lugol chromoendoscopy. Details: A small clinical trial in patients receiving a Lugol chromoendoscopy shows that spraying a vitamin C 2% solution after the application of the Lugol iodine 2% solution reduces the severity of mucosal irritation, heartburn, and pain when compared with using a normal saline spray after the Lugol iodine 2% solution (104030).
Esophageal cancer. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Population research has found that higher dietary intake of vitamin C is associated with reduced odds of esophageal adenocarcinoma. A 50 gram increase in dietary vitamin C intake is associated with a 13% reduced odds of esophageal cancer (34551,98770). However, a meta-analysis of clinical research shows that taking a vitamin C supplement in combination with beta-carotene and vitamin E does not reduce the risk of esophageal cancer (34581).
Exercise-induced asthma. Small clinical studies suggest that oral vitamin C may modestly improve symptoms in patients with exercise-induced asthma. Details: A meta-analysis of the available clinical research shows that vitamin C supplementation might reduce exercise-induced breathlessness when compared with placebo or control. However, the available research is of poor quality, and no clear conclusions can be drawn regarding its benefits for exercise-induced asthma (90409).
Exercise-induced muscle damage. It is unclear if oral vitamin C is beneficial in exercise-induced muscle damage. Details: A small clinical study in healthy females shows that taking vitamin C 1000 mg before moderate intensity cycling does not prevent muscle damage when compared with placebo (99837). Another small clinical study in endurance-trained runners shows that taking vitamin C 1000 mg and vitamin E (as alpha-tocopherol) 235 mg 2 hours prior to an exercise protocol does not reduce delayed onset muscle soreness or improve other markers of exercise-induced muscle damage when compared with placebo (109961).
Gallbladder disease. It is unclear if oral vitamin C reduces the risk of gallbladder disease. Details: Cross-sectional epidemiological evidence has found that vitamin C supplementation and increased vitamin C serum levels are associated with a decreased risk of developing gallbladder disease in females, but not males (5877).
Gastric cancer. It is unclear if dietary or supplemental vitamin C reduces the risk of gastric cancer. Details: Most population research has not found an association between DIETARY intake of vitamin C and gastric cancer risk (9194,10822,10819,90083). Also, clinical research shows that taking vitamin C supplements in combination with other antioxidants does not reduce the risk of gastric cancer or precancerous gastric lesions (14447,34581,90085). However, some research suggests that it might be associated with a reduced risk for specific forms of gastric cancer (9838,90083). One clinical study shows that taking vitamin C orally 500 mg daily for 6 months after eradication of Helicobacter pylori infection decreases the incidence of precancerous changes in stomach tissue when compared with no treatment (10359). Also, other clinical research shows that taking vitamin C orally 1 gram daily helps promote the regression of precancerous gastric lesions in people at high risk for gastric cancer (2579). In 2009, the US Food and Drug Administration (FDA) determined that it would allow a qualified health claim stating that vitamin C supplements may reduce the risk of gastric cancer. However, the FDA has concluded that it is highly uncertain that vitamin C supplements actually reduce the risk of gastric cancer (102332).
Gastritis. There is limited evidence on the oral use of vitamin C in omeprazole-induced corpus gastritis. Details: A small clinical study shows that taking vitamin C orally 1200 mg daily along with omeprazole decreases corpus gastritis associated with omeprazole therapy in patients with H. pylori infection (10360).
Gout. It is unclear if oral vitamin C helps to prevent or manage gout. Details: Population research in men has found that taking vitamin C 500-1500 mg daily from the diet and/or supplements is associated with up to a 34% reduced risk of gout when compared with less than 250 mg daily (16755). Also, men who ingest over 500 mg of vitamin C daily from the diet and supplements have serum uric acid levels that are slightly lower than men who consume less than 90 mg daily (16820). However, taking supplemental vitamin C 500 mg daily for 8 weeks does not seem to lower serum uric acid levels in patients who already have gout (90423).
Hearing loss. There is limited evidence on the intravenous use of vitamin C in idiopathic sudden sensorineural hearing loss. It is unclear if dietary vitamin C intake can affect the risk of hearing loss. Details: A small clinical study in patients with idiopathic sudden sensorineural hearing loss shows that receiving intravenous high-dose vitamin C 200 mg/kg daily in combination with steroid therapy for 10 days, followed by oral vitamin C 2000 mg daily for 30 days, increases recovery rate two-fold and modestly improves hearing threshold levels when compared with receiving steroid therapy only (90417). In addition, population research in females has found that high dietary intake of vitamin C is associated with a 22% increased risk of developing self-reported hearing loss over a 22-year period when compared with low intake (109807).
Heart transplant complications. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial shows that a combination of vitamin C 500 mg and vitamin E 400 IU, taken twice daily for 1 year starting within the first 2 years after cardiac transplant, reduced the progression of vasculopathy as measured by intravascular ultrasonography (IVUS) when compared with placebo. This suggests that the combination may help slow the progression of CAV (82826).
Hepatitis C. It is unclear if oral vitamin C is beneficial in patients with hepatitis C. Details: A small clinical study in patients with confirmed hepatitis C shows that taking vitamin C 1000 mg daily with conventional therapy (sofosbuvir plus daclatasvir) for 4 weeks improves serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), bilirubin, and albumin when compared with conventional therapy alone (109463).
HIV/AIDS. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small, low-quality study in men with HIV shows that taking vitamin C 250 mg daily in combination with vitamin A, beta-carotene, vitamin E, selenium, and coenzyme Q10 does not improve viral load, although it seems to improve markers of oxidative stress when compared to baseline. However, a 1000 mg dose of vitamin C, as well as higher doses of the other antioxidants, do not seem to provide any additional effect (9830).
HIV transmission. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A clinical study in HIV-positive mothers shows that taking vitamin B, vitamin C, and vitamin E daily during pregnancy and while breast-feeding for 20 weeks seems to reduce child mortality and HIV transmission through breast milk when compared with taking vitamin A (9801).
Hyperphosphatemia. Intravenous vitamin C might be beneficial for reducing phosphate levels in patients with end-stage renal disease. Details: A small clinical study in hemodialysis patients with elevated phosphorus levels suggests that administering vitamin C 500 mg intravenously three times weekly for 8 weeks reduces phosphorus levels about seven-fold when compared with placebo (90414).
Idiopathic interstitial pneumonia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical study in patients with idiopathic pulmonary fibrosis, a form of idiopathic interstitial pneumonia, shows that taking a combination of vitamin C 250 mg every other day, vitamin D 50,000 IU daily, and vitamin E 200 IU daily for 12 weeks improves some, but not all, measures of lung function and reduces markers of inflammation and oxidative stress when compared to baseline (109464). The validity of these findings is limited by a lack of placebo control group.
Infertility. It is unclear if oral vitamin C is beneficial in anovulatory females. Details: A very small clinical study suggests that taking vitamin C 400-1000 mg daily might improve fertility, resulting in ovulation and pregnancy in some anovulatory females, when compared to baseline (14018). The validity of these findings is limited by the small study size and lack of a comparator group. However, a very large observational study suggests that there is no association between dietary vitamin C intake and in-vitro fertilization (IVF) outcomes including good oocyte quality, embryo transfer success rates, clinical pregnancy rates, and successful term pregnancy rates in subfertile couples who are candidates for IVF (112097).
Male infertility. It is unclear if oral or intravenous vitamin C is beneficial in males with infertility. Details: A meta-analysis of three small, low-quality clinical trials in males with infertility shows that taking vitamin C up to 1000 mg daily for up to 12 weeks can improve sperm count, motility, and vitality, but does not seem to increase semen volume or sperm concentration, when compared with control (109461). It is unclear if vitamin C can increase pregnancy rates, as these studies did not assess this outcome. A retrospective study in males with or without varicocele-related infertility has found that taking a specific combination product containing vitamin C 90 mg, zinc 10 mg, L-carnitine fumarate 1725 mg, acetyl-L-carnitine 500 mg, coenzyme Q10 20 mg, folic acid 0.2 mg, selenium 0.05 mg, and vitamin B12 0.015 mg (Proxeed Plus, Sigma-Tau) orally twice daily for 6 months improves sperm count, sperm concentration, and sperm motility when compared with baseline. Improvement in semen parameters were greatest in subjects with more severe varicoceles. The validity of this study is limited by the lack of a comparator group (111296).
Mastalgia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in patients with mastalgia shows that taking a combination of vitamin C 100 mg, vitamin B12, and gamma-linolenic acid daily for 12 weeks does not improve the proportion of patients with minimal or no pain when compared with placebo (111059).
Melasma. It is unclear if topical vitamin C is beneficial in patients with melasma. Details: A small clinical study in patients with bilateral symmetrically distributed facial melasma shows that topical application of 0.5 mL of vitamin C (Cosmotech, Alpha Medical Cosmotech) following dermapen microneedling every 2 weeks for 6 weeks is similarly effective to tranexamic acid for improving melasma severity and pigmented, but not vascular, findings on dermoscopic examination (106939).
Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral vitamin C is beneficial in patients with NAFLD. Details: A clinical study in patients with NAFLD shows that taking vitamin C 250 mg, 1000 mg, or 2000 mg daily for 12 weeks improves some biochemical markers of liver health and glucose metabolism when compared with baseline. However, the improvement from baseline was similar between groups (106942).
Nonalcoholic steatohepatitis (NASH). Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Preliminary clinical research suggests vitamin C in combination with vitamin E might improve hepatic fibrosis in patients with NASH. However, it does not seem to decrease liver inflammation (14005).
Non-Hodgkin lymphoma. It is unclear if oral vitamin C reduces the risk of developing diffuse large B-cell lymphoma. Details: In one population study, higher dietary or supplemental intake of vitamin C was associated with a reduced risk of diffuse large B-cell lymphoma, a type of non-Hodgkin lymphoma, when compared with lower intake in postmenopausal adults (90945).
Oral cancer. It is unclear if oral vitamin C reduces the risk of developing oral cancer. Details: Population research has found that higher dietary intake of vitamin C is associated with a reduced risk of oral cancer (10821). However, clinical research has not shown benefit with oral vitamin C supplements. A small clinical trial in Japanese adults with oral leukoplakia shows that taking vitamin C 500 mg and beta-carotene 10 mg daily for 12 months does not reduce the development of oral cancer over 5 years when compared with vitamin C 50 mg daily (91384).
Oral leukoplakia. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: A small clinical trial in Japanese adults with oral leukoplakia shows that taking vitamin C 500 mg and beta-carotene 10 mg daily for 12 months does not improve leukoplakia symptoms or reduce the development of oral cancer over 5 years when compared with vitamin C 50 mg daily (91384).
Osteoarthritis. It is unclear if dietary vitamin C reduces the risk of developing osteoarthritis. Details: Observational research has found that increased vitamin C from dietary sources is associated with a reduced risk of cartilage loss and disease progression in people with osteoarthritis (5881).
Osteoporosis. It is unclear if dietary vitamin C improves bone density or reduces fracture risk in patients at risk for osteoporosis. Details: Some cross-sectional observational research in postmenopausal patients without a history of smoking or estrogen use has found that higher serum vitamin C levels are associated with lower bone mineral density (9828). However, other observational research in a larger population of adults at risk for osteoporosis has found that higher dietary vitamin C intake is not associated with fracture risk (104415).
Ovarian cancer. Dietary vitamin C might not affect the risk of ovarian cancer. Details: Epidemiological research has found that dietary vitamin C intake is not linked with ovarian cancer risk (9193,102977).
Pancreatitis. It is unclear if intravenous vitamin C is beneficial in patients with acute pancreatitis. Details: A small meta-analysis of clinical studies in patients with acute pancreatitis shows that intravenous vitamin C does not improve the odds of developing organ failure when compared with placebo or no intervention. Intravenous vitamin C seems to reduce hospital stay, but not in-hospital mortality (106941).
Parkinson disease. Dietary vitamin C might not affect the risk of developing this condition. Details: Observational research has found that moderate or high dietary intake of vitamin C is not associated with a reduced risk of Parkinson disease (83316).
Periodontitis. Oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. It is also unclear if dietary vitamin C reduces the risk of periodontitis. Details: A small clinical study in patients with moderate or advanced periodontitis shows that taking a supplement containing vitamin C 100 mg, alpha-lipoic acid, coenzyme Q10, cranberry extract, grapeseed extract, selenium, vitamin E, and zinc twice daily for 8 weeks in addition to standard nonsurgical therapy does not improve periodontal indices including bleeding on probing, gingival recession, plaque index, or inflammation, among others, when compared with placebo (111708). It is unclear if these effects are due to vitamin C, other ingredients, or the combination. There is also interest in whether dietary vitamin C intake impacts the risk of periodontitis. Observational research in US adults has found that individuals with dietary intake of vitamin C in the third quartile, but not the second or fourth quartiles, have lower odds of periodontitis when compared with vitamin C intake in the lowest quartile. Furthermore, the investigators identified a non-linear relationship between vitamin C intake and periodontitis risk, suggesting that individuals with intakes either much lower or much higher than 158 mg daily are at increased risk of developing periodontitis (109958).
Peripheral arterial disease (PAD). It is unclear if dietary vitamin C helps to reduce the risk of developing PAD. Details: In females, epidemiological evidence has found that dietary intake of vitamin C of 142 mg daily or greater is associated with a 36% reduced risk of PAD when compared with lower intake levels of less than 80 mg daily (10130).
Physical performance. It is unclear if oral vitamin C helps to improve physical performance and muscle strength in older people. Details: Population research has found that higher intake of dietary vitamin C is associated with improved physical performance and muscle strength in elderly people (14006). In contrast, a small clinical study in elderly men undergoing strength training shows that taking vitamin C 1000 mg and vitamin E 258IU daily for 12 weeks does not increase strength, and might even attenuate increases in muscle mass, when compared with strength training alone (96701).
Pneumonia. It is unclear if oral vitamin C helps to prevent pneumonia. Details: A meta-analysis of two small, low-quality clinical studies in children shows that vitamin C does not seem to reduce the occurrence of pneumonia when compared to control (104033).
Postoperative recovery. It is unclear if oral or intravenous vitamin C improves postoperative recovery. Details: Meta-analyses of clinical research show that oral or intravenous vitamin C can shorten the duration of hospitalization after cardiac surgery when compared with control (91233,96703). However, other research shows no decrease in intensive care or hospital stay with vitamin C supplementation (96705). A meta-analysis of 37 clinical trials in adults undergoing low- to high-risk noncardiac surgery (i.e., orthopedic, abdominal, gynecologic, or kidney transplantation), shows that receiving perioperative vitamin C, either orally or intravenously, does not improve duration of hospitalization or overall mortality when compared with control (108087). There's also some limited evidence that vitamin C might reduce postoperative pulmonary complications such as lung infection, pleural effusion, and pneumothorax. A small clinical trial in low-risk cardiac surgery patients shows that receiving intravenous vitamin C 1 gram 10 minutes after anesthesia might slightly reduce the rate of postoperative pulmonary complications when compared with receiving a saline injection (104034).
Postoperative swelling. It is unclear if vitamin C reduces postoperative swelling after dental surgery. Details: A small observational study in adults undergoing surgery for wisdom tooth extraction shows that taking vitamin C 500 mg three times daily for 7 days in addition to standard treatment reduces swelling 7 days after surgery when compared with control. However, vitamin C does not seem to reduce swelling 3 days after surgery when compared with control, suggesting that longer durations are needed for anti-inflammatory effects (113664).
Premature rupture of membranes (PROM). Oral vitamin C seems to reduce the risk of PROM in some patients; however, the addition of oral vitamin E seems to negate any benefit. Details: A meta-analysis of clinical research shows that taking vitamin C alone decreases the risk of both term and preterm PROM by 45% and 34%, respectively, when compared with placebo or control (96707). Also, a more recent clinical study in patients with a history of PROM shows that taking vitamin C 100 mg daily, starting at 14 weeks' gestation, increases the gestational age at recurrent PROM by around 1 week and increases the gestational age at birth by around 1.3 weeks when compared with placebo (109960). Taking vitamin C in combination with vitamin E, however, does not seem to reduce the risk of term or preterm PROM; some research suggests that it might even increase the risk of non-preterm PROM (83472,96707). However, other research shows that taking vitamin C 1000 mg plus vitamin E 400 IU daily, beginning at 24 to 34 weeks gestation and continuing until delivery, may help increase the latency period until delivery by 5 days and increase gestational age at delivery by almost 1 week when compared with placebo in patients with preterm PROM (90078).
Pressure ulcers. It is unclear if oral vitamin C, when used alone or in combination with other ingredients, can improve the healing of pressure ulcers. Details: A small clinical study in institutionalized patients with pressure ulcers shows that taking vitamin C 500 mg twice daily for 12 weeks does not improve wound closure or increase healing rates when compared with vitamin C 10 mg twice daily (83617). Oral vitamin C has also been evaluated in combination with other ingredients for the treatment of grade II-IV pressure ulcers. Two small clinical studies in hospitalized patients with pressure ulcers shows that administering an oral nutritional supplement enriched with vitamin C, L-arginine, and zinc improves ulcer healing when compared with a standard diet (31953,87173). Also, clinical research in patients living in long-term care facilities shows that taking an oral nutritional supplement enriched in protein, vitamin C, L-arginine, and zinc daily for 9 weeks reduces ulcer area and decreases oozing when compared to baseline (32045). The validity of this finding is limited by the lack of a comparator group.
Radiation proctopathy. Oral vitamin C has only been evaluated in combination with vitamin E; its effect when used alone is unclear. Details: A small clinical study in patients with chronic radiation proctitis shows that vitamin C 500 mg plus vitamin E 400 IU three times daily might improve symptoms when compared with baseline (9825). The validity of these findings is limited by the lack of a comparator group.
Renal cell carcinoma. It is unclear if increased dietary intake of vitamin C helps to reduce the risk of renal cell carcinoma. Details: Population research has found that increased dietary intake of vitamin C is associated with a 12% reduced risk of renal cell carcinoma (98779).
Respiratory tract infections. It is unclear if oral vitamin C is beneficial for preventing respiratory tract infections or reducing the duration of these infections. Details: A meta-analysis of clinical research in children and adults shows that, when compared with placebo, oral vitamin C supplementation reduces the average number of symptomatic days per individual, but does not reduce the average symptom days per respiratory episode. Also, vitamin C intake does not reduce the incidence or severity of respiratory disease or improve recovery in hospitalized patients with respiratory tract infections (108077). The validity of this trial is limited by the high heterogeneity of included studies, which evaluated various vitamin C regimens, ranging from 100 mg to 8 grams daily, as preventive therapy or as an adjuvant to active treatment. A clinical study in children aged 3-10 years shows that taking vitamin C 50 mg in combination with a specific product (Lab4) containing Lactobacillus acidophilus, Bifidobacterium bifidum, and Bifidobacterium animalis subsp. lactis daily for 6 months reduces the incidence of cough and sore throat by 16% and 20%, respectively, when compared with placebo. However, it did not improve total symptoms, nasal congestion, nasal discharge, or sneezing. Also, aside from a 33% reduction in the average number of days with a sore throat, daily supplementation does not reduce the duration of individual symptoms or total symptoms (106943). It is unclear if these effects are due to vitamin C, the probiotics, or the combination.
Restless legs syndrome (RLS). It is unclear if oral vitamin C helps to reduce symptoms of stress. Details: A small clinical study in hemodialysis patients with RLS shows that taking vitamin C 200 mg daily, alone or in combination with vitamin E 400 mg, for 8 weeks reduces the severity of RLS when compared with placebo (90093). More research is needed to determine if vitamin C is beneficial in treating RLS that is not associated with hemodialysis.
Smoking cessation. It is unclear whether supplemental vitamin C improves lung function in the offspring of pregnant adults with tobacco use disorder. Details: A meta-analysis of large clinical studies in pregnant adults who smoke at least one cigarette daily shows that taking supplemental vitamin C 500 mg daily during pregnancy reduces lower airway resistance and improves lung capacity of the offspring but does not improve airway obstruction when compared with control (113670).
Sunburn. Topical and oral vitamin C has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: Taking vitamin C orally in combination with vitamin E seems to prevent ultraviolet (UV) radiation-induced erythema (sunburn) (4715,4716). Vitamin C in combination with high dose oral RRR-alpha-tocopherol (natural vitamin E) seems to protect against skin inflammation after exposure to UV radiation (4715). Also, applying topical vitamin C in combination with topical vitamin E and melatonin seems to provide modest photoprotective effects when used prior to UV exposure. However, it has no effect when used during or after UV exposure (4713,4714).
Stress. It is unclear if oral vitamin C helps to reduce symptoms of stress. Details: A small clinical study in healthy adults shows that taking vitamin C 3000 mg daily for 14 days modestly reduces blood pressure and subjective stress response to psychological stress when compared with placebo (10353).
Stroke. Observational research has found that although taking vitamin C supplements does not seem to be beneficial, eating more vitamin C-rich food is linked with reduced risk of stroke. Details: Lower plasma levels of vitamin C have been associated with increased stroke risk (90408). Additionally, population research has found that higher dietary intake of vitamin C is associated with a 8% to 19% reduction in stroke risk when compared to lower intake (90408,109779). This reduction appears to be dose-dependent, with each 100 mg/day increase in dietary vitamin C intake associated with about a 17% reduction (90408). However, taking vitamin C supplements has not been found to be associated with reduced stroke risk (1449,90408).
Tetanus. It is unclear if intravenous vitamin C helps to reduce symptoms of tetanus. Details: A low quality clinical trial in children and young adults with tetanus shows that intravenous vitamin C 1 gram daily along with conventional treatment reduces fatality when compared to control (21539).
Tooth extraction. It is unclear if oral vitamin C is beneficial for reducing pain or improving healing after tooth extraction. Details: A small clinical study in healthy patients aged 14-41 years who are undergoing bilateral premolar extraction shows that taking vitamin C 200 mg three times daily, beginning immediately after extraction and continued for 10 days, improves pain on days 1-3, and may reduce mesio-distal wound size between days 1 and 7, when compared with placebo, but not when compared with vitamin C 500 mg three times daily. A dose of 500 mg three times daily did not improve pain scores or extraction wound healing when compared with placebo (108084). The validity of this trial is limited by the short duration of treatment; additionally, this study did not report baseline vitamin C levels.
Urinary tract infections (UTIs). Although there is interest in using oral vitamin C for UTIs, there is insufficient reliable information about the clinical effects of vitamin C for this condition.
Vascular dementia. It is unclear if oral vitamin C reduces the risk of vascular dementia. Details: Population research has found that supplemental intake of vitamin C and vitamin E is associated with a reduced risk of vascular dementia in Japanese-American men (4636). However, when cases in which dementia was diagnosed prior to the study are excluded from data analysis, intake of vitamin C and vitamin E is not associated with a reduced risk of vascular dementia in these patients (9824).
Wound healing. It is unclear if oral vitamin C improves the healing of chronic foot ulcers. It is also unclear if intravenous vitamin C improves healing of surgical wounds after total abdominal hysterectomy. Details: A very small clinical study in adults with chronic foot ulcers shows that taking slow-release vitamin C 500 mg daily for 8 weeks seems to result in a median of 100% ulcer healing, compared with a median of 14% ulcer healing in patients taking glucosamine 1000 mg daily (105456). This finding is limited due to the small and heterogeneous patient population, which included patients with diabetes, vascular disease, and/or vitamin C deficiency. Another small clinical study in patients undergoing total abdominal hysterectomy shows that administration of intravenous vitamin C 1 gram the night before surgery and 1 gram during surgery does not reduce the rate of surgical site infection or wound dehiscence when compared with placebo (109465). However, this study may not have been adequately powered to detect differences between groups. More evidence is needed to rate vitamin C for these uses.

AGARICUS MUSHROOM (Agaricus (Agaricus blazei Murrill) fruiting body powder)

Safety view details

Below is general information about the safety of the known ingredients contained in the product Mushroom Emperors. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.

POSSIBLY SAFE ...when used orally and appropriately. Agaricus mushroom extract has been safely used in doses up to 1500 mg daily for up to 12 months (15404,15421,94715,94716,94719,94721). A specific agaricus lyophilized powder product (Sen-Sei-Ro Powder Gold, Kyowa Wellness Co., Ltd.) has been safely used in doses up to 5.4 grams daily for 6 months (17185).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

BLACK HOOF MUSHROOM (Meshima (Phellinus linteus) fruiting body extract)

POSSIBLY SAFE ...when used orally and appropriately. Black hoof mushroom extract has been used safely in doses of 1 or 2 grams daily for up to 8 weeks (111930,111931).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

There is insufficient reliable information available about the safety of chaga.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

CORDYCEPS (Cordyceps (Cordyceps sinensis) mycelium powder)

POSSIBLY SAFE ...when used orally and appropriately. Cordyceps has been used with apparent safety in doses of 3-6 grams daily for up to 1 year (12,12095,92828,95905,105076,111903).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

MAITAKE MUSHROOM (Maitake fruiting body powder, Maitake fruiting body standardized extract, Maitake fruiting body standardized extract)

POSSIBLY SAFE ...when used orally and appropriately as extracts. A maitake mushroom extract 3 mg/kg twice daily has been used safely for up to 12 weeks (92843). Doses up to 5 mg/kg twice daily of another maitake mushroom extract have been used safely for up to 3 weeks (61239). Maitake mushroom polysaccharides (MMP) 1-1.5 grams daily have also been used safely for up to 2 years (8188).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

PORIA MUSHROOM (Poria (Poria cocus) Sclerotium extract)

There is insufficient reliable information available about the safety of poria mushroom.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

REISHI MUSHROOM (Reishi (Ganoderma lucidum) fruiting body double extract)

POSSIBLY SAFE ...when an extract of reishi mushroom is used orally and appropriately for up to one year (12,5485,70767,70774,70786,70799,70800,70801,70802). ...when whole powdered reishi mushroom is used orally and appropriately for up to 16 weeks (70776,70799,70800,70801,91433,91435,91436,91437,108309).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using

SHIITAKE MUSHROOM (Shiitake (Lentinus edodes) fruiting body powder)

LIKELY SAFE ...when consumed in typical food amounts (6).

POSSIBLY SAFE .... ..when the shiitake mushroom extract AHCC is used orally and appropriately. AHCC 4.5-6 grams daily has been used with apparent safety in clinical trials lasting up to 6 months (22926,30419). Population research identified no safety concerns with the use of AHCC 3 grams daily for up to 9 years (30353,94830).

POSSIBLY UNSAFE ...when shiitake mushroom powder is used orally in medicinal amounts. Ingestion of shiitake mushroom powder 4 grams daily for 10 weeks can cause eosinophilia (1149). ...when uncooked shiitake mushroom is ingested. The lentinan component, which is broken down by heat, can cause toxic reactions, including shiitake dermatitis (94354).

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid consuming greater than food amounts.

TURKEY TAIL MUSHROOM (Coriolus (Coriolus versicolor) fruiting body extract)

LIKELY SAFE ...when turkey tail mushroom is used orally and appropriately (5477). ...when polysaccharide krestin (PSK) and polysaccharide peptide (PSP) isolates of turkey tail mushroom are used orally and appropriately (1635,1636,1640,1641,1648,1649,1650,1651,1652,1653,1654) (1655,1656,1657,1658,1659,1660,1661,1662,70167,70168,70171,70188,70200,94076). There is insufficient reliable information available about the safety of turkey tail mushroom when used topically or intravaginally.

PREGNANCY AND LACTATION:
Insufficient reliable information available; avoid using.

VITAMIN C

LIKELY SAFE ...when used orally, topically, intramuscularly, or intravenously and appropriately. Vitamin C is safe when taken orally in doses below the tolerable upper intake level (UL). Tell patients not to exceed the UL of 2000 mg daily (1959,4713,4714,4844). ...when used intravenously or intramuscularly and appropriately. Injectable vitamin C is an FDA-approved prescription product (15).

POSSIBLY UNSAFE ...when used orally in excessive doses. Doses greater than the tolerable upper intake level (UL) of 2000 mg daily can significantly increase the risk of adverse effects such as osmotic diarrhea and gastrointestinal upset (4844).

CHILDREN: LIKELY SAFE
when used orally and appropriately (4844,10352,14443).

CHILDREN: POSSIBLY UNSAFE
when used orally in excessive amounts. Tell patients not to use doses above the tolerable upper intake level (UL) of 400 mg daily for children ages 1 to 3 years, 650 mg daily for children 4 to 8 years, 1200 mg daily for children 9 to 13 years, and 1800 mg daily for adolescents 14 to 18 years. Higher doses can cause osmotic diarrhea and gastrointestinal upset (4844).

PREGNANCY AND LACTATION: LIKELY SAFE
when used orally and appropriately (4844).

PREGNANCY AND LACTATION: POSSIBLY UNSAFE
when used orally in excessive doses. Tell patients over age 19 not to use doses exceeding the UL of 2000 mg daily when pregnant or breast-feeding and for those 14-18 years of age not to use doses exceeding 1800 mg daily when pregnant or breast-feeding. Higher doses can cause osmotic diarrhea and gastrointestinal upset. Large doses of vitamin C during pregnancy can also cause newborn scurvy (4844); avoid using.

AGARICUS MUSHROOM (Agaricus (Agaricus blazei Murrill) fruiting body powder)

Interactions with Drugs view details

Below is general information about the interactions of the known ingredients contained in the product Mushroom Emperors. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.

ANTIDIABETES DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, taking agaricus mushroom with antidiabetes drugs might increase the risk of hypoglycemia.

Details

In one clinical study in patients with type 2 diabetes who are stabilized on conventional oral hypoglycemic agents, 3 of 29 patients taking an agaricus mushroom extract 500 mg three times daily for 12 weeks reported hypoglycemia, compared to one of 29 patients in the placebo group (15421).

BLACK HOOF MUSHROOM (Meshima (Phellinus linteus) fruiting body extract)

CYTOCHROME P450 1A1 (CYP1A1) SUBSTRATES

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP1A1 substrates.

Details

In vitro, polysaccharides from black hoof mushroom grown in culture inhibit CYP1A1 (27612). This effect has not been reported in humans.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP1A2 substrates.

Details

In vitro, polysaccharides from black hoof mushroom grown in culture inhibit CYP1A2 (27612). This effect has not been reported in humans.

CYTOCHROME P450 2B1 (CYP2B1) SUBSTRATES

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP2B1 substrates.

Details

In vitro, polysaccharides from black hoof mushroom grown in culture inhibit CYP2B1 (27612). This effect has not been reported in humans.

CYTOCHROME P450 2E1 (CYP2E1) SUBSTRATES

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, black hoof mushroom might increase the levels and clinical effects of CYP2E1 substrates.

Details

In vitro, polysaccharides from black hoof mushroom grown in culture inhibit CYP2E1 (27612). This effect has not been reported in humans.

IMMUNOSUPPRESSANTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, black hoof mushroom might reduce the effects of immunosuppressant medications.

Details

In animal research, polysaccharides from black hoof mushroom and black hoof mushroom extract stimulate immune responses (27600,27601,27602,27613,91009).

ANTICOAGULANT/ANTIPLATELET DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, chaga may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.

Details

In vitro and animal research suggests that chaga extract can inhibit platelet aggregation (26260). This effect has not been reported in humans.

ANTIDIABETES DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, taking chaga with antidiabetes drugs might increase the risk of hypoglycemia.

Details

Animal research suggests that chaga might decrease blood glucose levels and increase insulin levels (26253,111924,111925,111927). This has not been reported in humans.

IMMUNOSUPPRESSANTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, chaga might interfere with immunosuppressive therapy.

Details

In vitro research suggests that certain constituents of chaga stimulate immune function (26263). This has not been reported in humans.

CORDYCEPS (Cordyceps (Cordyceps sinensis) mycelium powder)

ANTICOAGULANT/ANTIPLATELET DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, cordyceps may increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.

Details

In vitro and animal research suggests that cordyceps extract inhibits platelet aggregation and function (3429,46112). However, this interaction has not been reported in humans.

IMMUNOSUPPRESSANTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = B

Theoretically, concurrent use of cordyceps might interfere with immunosuppressive therapy.

Details

Animal and in vitro research suggests that cordyceps stimulates the immune system (3403,3404,3414,3431,3432). However, limited clinical research suggests that taking cordyceps may lower the necessary therapeutic dose of the immunosuppressant cyclosporine (92828), which suggests that cordyceps may have an immunosuppressive effect.

TESTOSTERONE

Interaction Rating = Minor Be watchful with this combination.

Severity = Mild • Occurrence = Possible • Level of Evidence = D

Theoretically, concurrent use of cordyceps and testosterone might have additive effects.

Details

Animal research suggests that cordyceps can increase testosterone levels (46087). The clinical significance of this finding is unclear.

LION'S MANE MUSHROOM (Lion's Mane (Hericium erinaceus) fruiting body powder, Lion's Mane fruiting body standardized extract)

ANTICOAGULANT/ANTIPLATELET DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, lion's mane mushroom may increase the risk of bleeding when used with anticoagulant/antiplatelet drugs.

Details

In vitro research suggests that lion's mane mushroom extracts can inhibit platelet aggregation (92619).

ANTIDIABETES DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, lion's mane mushroom may have additive effects when used with antidiabetes drugs.

Details

Animal research suggests that an aqueous extract of lion's mane mushroom can reduce serum glucose and increase serum insulin (91996).

IMMUNOSUPPRESSANTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, concurrent use of lion's mane mushroom might interfere with immunosuppressive therapy.

Details

In animal and in vitro research, lion's mane mushroom polysaccharides stimulate the immune system (91933,111933).

MAITAKE MUSHROOM (Maitake fruiting body powder, Maitake fruiting body standardized extract, Maitake fruiting body standardized extract)

ANTIDIABETES DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = B

Theoretically, combining maitake mushroom with antidiabetes drugs might increase the risk of hypoglycemia.

Details

Clinical research shows that taking maitake mushroom polysaccharide (MMP) can lower blood glucose levels in patients with types 2 diabetes (8188).

ANTIHYPERTENSIVE DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, combining maitake mushroom with antihypertensive drugs might increase the risk of hypotension.

Details

Animal research shows that maitake mushroom can lower blood pressure (1213,1214,61226).

WARFARIN (Coumadin)

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

There is limited evidence that maitake mushroom may increase the anticoagulant effects of warfarin.

Details

In a case report, a patient previously stabilized on warfarin developed an elevated international normalized ratio (INR) of 5.1 after taking maitake mushroom (Grifron-Pro Maitake D-Fraction) 1 drop/kg daily in three divided doses for one week. The elevated INR resolved after holding warfarin for two days, then reducing the dose by 11%. It is thought that the beta-glucan constituent of maitake mushroom might cause warfarin dissociation from proteins, resulting in increased free warfarin levels and increased warfarin effects (17209).

PORIA MUSHROOM (Poria (Poria cocus) Sclerotium extract)

ANTICHOLINERGIC DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, poria mushroom might decrease the clinical effects of anticholinergic drugs.

Details

In animal research, poria mushroom essential oil reduces acetylcholinesterase activity (111917). This interaction has not been shown in humans.

CHOLINERGIC DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, poria mushroom might have additive effects when used with cholinergic drugs.

Details

In animal research, poria mushroom essential oil reduces acetylcholinesterase activity (111917). This interaction has not been shown in humans.

CNS DEPRESSANTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, taking poria mushroom extract may enhance the therapeutic and adverse effects of sedatives.

Details

Animal research shows that poria mushroom extract has sedative properties (111916). This interaction has not been shown in humans.

REISHI MUSHROOM (Reishi (Ganoderma lucidum) fruiting body double extract)

ANTICOAGULANT/ANTIPLATELET DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, high doses of reishi mushroom might increase the risk of bleeding.

Details

A dose of 1.5 grams daily of reishi mushroom does not seem to decrease platelet aggregation, but a higher dose of 3 grams daily does (5476,13235).

ANTIDIABETES DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, reishi mushroom might have additive effects with antidiabetes drugs.

Details

Animal research suggests that reishi mushroom decreases blood sugar (70769). However, in patients with type 2 diabetes, taking reishi mushroom does not reduce fasting glucose levels, and its effects on glycated hemoglobin are inconsistent (70801,91435).

ANTIHYPERTENSIVE DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, concurrent use of reishi mushroom with antihypertensive drugs might increase the risk of hypotension.

Details

Reishi mushroom has shown hypotensive activity in animal research (5488,70784). Clinical evidence suggests that reishi mushroom reduces blood pressure in some, but not all, patients with hypertension (70786,70802).

SHIITAKE MUSHROOM (Shiitake (Lentinus edodes) fruiting body powder)

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, shiitake mushroom might decrease levels of drugs metabolized by CYP2D6.

Details

In vitro studies suggest that the shiitake mushroom extract AHCC might induce the CYP2D6 enzyme (30369,30420). This effect has not been reported in humans.

IMMUNOSUPPRESSANTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, taking shiitake mushroom might decrease the effects of immunosuppressive therapy.

Details

In vitro evidence suggests that shiitake mushroom extracts stimulate immune function (30351,30358,30360,30361,30366,30367,30368,30371,30376,30379,30381,30382,30416,30418) (74769,74783,74876,94245).

TURKEY TAIL MUSHROOM (Coriolus (Coriolus versicolor) fruiting body extract)

ANTIDIABETES DRUGS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, taking turkey tail mushroom with antidiabetes drugs might increase the risk of hypoglycemia.

Details

Animal research suggests that turkey tail mushroom and a polysaccharide component can have hypoglycemic effects (108307,111907).

CYCLOPHOSPHAMIDE

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, the polysaccharide peptide (PSP) component of turkey tail mushroom might increase exposure to cyclophosphamide.

Details

Some animal research shows that the PSP component of turkey tail mushroom can increase the area under the concentration-time curve (AUC) of cyclophosphamide by 44% to 50% and the half-life by 34% to 43% (96569). This interaction could potentially increase the effects and adverse effects of cyclophosphamide. However, it is not known whether PSP affects the levels of the active metabolites of cyclophosphamide that are responsible for its clinical activity.

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

Interaction Rating = Minor Be watchful with this combination.

Severity = Insignificant • Occurrence = Possible • Level of Evidence = D

Theoretically, the polysaccharide peptide (PSP) component of turkey tail mushroom might inhibit CYP2C9.

Details

Laboratory research suggests that the PSP component of turkey tail mushroom dose-dependently inhibits CYP2C9 (94075). Theoretically, taking PSP with drugs metabolized by CYP2C9 might increase drug levels and the risk of adverse effects. However, this has not been reported in humans.

TAMOXIFEN (Nolvadex)

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, the polysaccharide peptide (PSP) component of turkey tail mushroom might interfere with the absorption of tamoxifen.

Details

Animal research suggests that PSP increases the time to reach maximum concentration of a single dose of tamoxifen by about 9.5 hours, or 228%. When repeated doses of tamoxifen were given, the time to reach maximum concentration was increased by about 5.6 hours, or 93%. However, PSP did not affect the maximum concentration or the area under the curve of tamoxifen (108308).

VITAMIN C

ACETAMINOPHEN (Tylenol, others)

Interaction Rating = Minor Be watchful with this combination.

Severity = Insignificant • Occurrence = Probable • Level of Evidence = B

High-dose vitamin C might slightly prolong the clearance of acetaminophen.

Details

A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases (6451). This effect is not likely to be clinically significant.

ALKYLATING AGENTS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.

Details

The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa (391). In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells (14012,14013). More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

ALUMINUM

Interaction Rating = Moderate Be cautious with this combination.

Severity = Mild • Occurrence = Probable • Level of Evidence = B

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.

Details

Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption (10549,10550,10551,21556). In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely (10549). Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

ANTITUMOR ANTIBIOTICS

Interaction Rating = Moderate Be cautious with this combination.

Severity = High • Occurrence = Possible • Level of Evidence = D

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.

Details

The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin (391). In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells (14012,14013). More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

ASPIRIN

Interaction Rating = Minor Be watchful with this combination.

Severity = Insignificant • Occurrence = Possible • Level of Evidence = B

Acidification of the urine by vitamin C might increase aspirin levels.

Details

It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels (3046). However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion (10588,10589), suggesting this interaction is not clinically significant.

CHOLINE MAGNESIUM TRISALICYLATE (Trilisate)

Interaction Rating = Minor Be watchful with this combination.

Severity = Insignificant • Occurrence = Possible • Level of Evidence = B

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.

Details

It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels (3046,4531). However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion (10588,10589), suggesting this interaction probably is not clinically significant.

ESTROGENS

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Probable • Level of Evidence = B

Vitamin C might increase blood levels of estrogens.

Details

Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products (129,130,11161). It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall (129,11161). When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements (11161). Monitor these patients for estrogen-related side effects.

FLUPHENAZINE (Prolixin)

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

Theoretically, vitamin C might decrease levels of fluphenazine.

Details

In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started (11017). The mechanism is not known, and there is no further data to confirm this interaction.

INDINAVIR (Crixivan)

Interaction Rating = Moderate Be cautious with this combination.

Severity = Mild • Occurrence = Probable • Level of Evidence = B

Vitamin C can modestly reduce indinavir levels.

Details

One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown (11300,93578).

LEVOTHYROXINE (Synthroid, others)

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Probable • Level of Evidence = B

Vitamin C can increase levothyroxine absorption.

Details

Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH (102978).

NIACIN

Interaction Rating = Minor Be watchful with this combination.

Severity = Mild • Occurrence = Possible • Level of Evidence = A

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.

Details

A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease (7388,11537). It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

SALSALATE (Disalcid)

Interaction Rating = Minor Be watchful with this combination.

Severity = Insignificant • Occurrence = Possible • Level of Evidence = B

Acidification of the urine by vitamin C might increase salsalate levels.

Details

It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels (3046). However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion (10588,10589), suggesting this interaction probably is not clinically significant.

WARFARIN (Coumadin)

Interaction Rating = Moderate Be cautious with this combination.

Severity = Moderate • Occurrence = Possible • Level of Evidence = D

High-dose vitamin C might reduce the levels and effectiveness of warfarin.

Details

Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption (11566). There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time (9804,9806). Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant (9805,9806,11566,11567). However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR) (90942). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Report an Adverse Reaction to Mushroom Emperors

Adverse Effects view details

Below is general information about the adverse effects of the known ingredients contained in the product Mushroom Emperors. Some ingredients may not be listed. This information does NOT represent a recommendation for or a test of this specific product as a whole.

AGARICUS MUSHROOM (Agaricus (Agaricus blazei Murrill) fruiting body powder)

General ...Orally, agaricus mushroom is generally well tolerated.
Most Common Adverse Effects:
Orally: Abdominal discomfort, diarrhea, and nausea.
Serious Adverse Effects (Rare):
Orally: Allergic reactions, hepatotoxicity, interstitial lung disease (ILD).

Gastrointestinal ...In one clinical trial, mild gastrointestinal side effects such as nausea, diarrhea, and abdominal discomfort were reported in 6 of 78 patients taking a specific agaricus powder product , Ltd.) 1.8-5.4 grams orally daily for 60 days. The causal relationship between this agaricus mushroom product and the associated gastrointestinal adverse effect was determined to be possible or probable in each case (17185).

Hepatic ...Three cases of severe hepatotoxicity have been reported in females with ovarian or breast cancer receiving chemotherapy who also took agaricus mushroom supplements. Two of the patients had increases in liver function tests a few days after starting agaricus mushroom, which then progressed rapidly to fatal, fulminant hepatitis. One of these patients was also an asymptomatic carrier of hepatitis B virus. In the third case, liver function improved when agaricus mushroom was stopped, worsened when it was restarted, and then recovered fully when the supplement was stopped permanently (16458).

Immunologic ...An allergic reaction has been reported in a female who took a specific agaricus powder product , Ltd.) 1.8 grams daily by mouth for 2 months. The patient developed an urticarial papular rash which resolved when the product was discontinued (17185). Allergic contact cheilitis was also reported in a patient taking a homemade agaricus mushroom extract orally. The reaction resolved upon discontinuation of agaricus mushroom (94720).

Pulmonary/Respiratory ...There is one case report of interstitial lung disease associated with the use of agaricus mushroom for approximately one month in a male with pancreatic ductal adenocarcinoma being treated with gemcitabine. Drug-induced lymphocyte stimulation test (DLST) was positive for agaricus mushroom extract and not gemcitabine. Pneumonitis improved upon discontinuation of agaricus mushroom (108313).

BLACK HOOF MUSHROOM (Meshima (Phellinus linteus) fruiting body extract)

General ...Black hoof mushroom seems to be well tolerated. No adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.

General ...There is limited reliable information available regarding the adverse effects of chaga.

Renal ...Orally, there have been two cases of kidney failure and one case of acute nephropathy related to excessive chaga consumption, which contains high concentrations of oxalate (96566,105246,108756).

CORDYCEPS (Cordyceps (Cordyceps sinensis) mycelium powder)

General ...Orally, cordyceps seems to be generally well tolerated when used for up to 1 year.
Most Common Adverse Effects:
Orally: Abdominal discomfort, constipation, diarrhea.

Gastrointestinal ...Orally, cordyceps has been associated with diarrhea, constipation, abdominal discomfort, dry mouth, and throat discomfort in clinical research. However, these events were uncommon, and in some cases symptoms could be reduced by taking cordyceps after eating (92829,105076,109705).

Hematologic ...Two cases of lead poisoning, characterized by loss of appetite and other symptoms, have been reported for patients taking cordyceps powder. After discontinuing cordyceps supplementation, both patients were treated with chelating agents (46135).

Hepatic ...There is a case report of acute cholestatic hepatitis probably associated with the use of a product containing cordyceps. The 64-year-old male was asymptomatic except for jaundice and laboratory markers and recovered once the supplement was stopped. However, it is unclear whether the hepatitis is associated with the cordyceps or with an unknown contaminant (109704).

Renal ...One case of a mild increase in serum creatinine level (< 30%) has been reported (95905).

LION'S MANE MUSHROOM (Lion's Mane (Hericium erinaceus) fruiting body powder, Lion's Mane fruiting body standardized extract)

General ...Orally, lion's mane mushroom is generally well tolerated.
Most Common Adverse Effects:
Orally: Gastrointestinal discomfort, nausea, skin rash.

Dermatologic ...Orally, lion's mane mushroom may cause skin rash (105546).

Gastrointestinal ...Orally, lion's mane mushroom may cause gastrointestinal discomfort and nausea (91999,105546).

MAITAKE MUSHROOM (Maitake fruiting body powder, Maitake fruiting body standardized extract, Maitake fruiting body standardized extract)

General ...Orally, maitake mushroom is generally well tolerated.
Most Common Adverse Effects:
Orally: Gastrointestinal effects, including diarrhea and epigastric pain.

Dermatologic ...In a clinical trial, one patient experienced rash and pruritus after two doses of maitake mushroom polysaccharide extract. The allergic reaction cleared without intervention (61239).

Gastrointestinal ...In clinical research of a polysaccharide extract from maitake mushroom, one patient reported nausea (61239) and 2 out of 26 reported epigastric pain (17131). In a clinical trial of a liquid extract from maitake mushroom, 2 out of 21 patients experienced diarrhea, and one experienced nausea. One patient withdrew from the study due to diarrhea (92843).

Immunologic ...In a clinical trial of a liquid extract from maitake mushroom, 4 out of 21 patients experienced eosinophilia (92843).

Musculoskeletal ...In a clinical trial of a polysaccharide extract from maitake mushroom, one patient reported joint swelling (61239).

Pulmonary/Respiratory ...There is one case of occupational hypersensitivity pneumonitis (HP) caused by maitake mushroom spores (61228).

PORIA MUSHROOM (Poria (Poria cocus) Sclerotium extract)

General ...Orally, poria mushroom seems to be well tolerated. However, a thorough evaluation of safety outcomes has not been conducted.

Immunologic ...Allergic reactions have been reported rarely, including allergic rhinitis and allergic asthma (12).

REISHI MUSHROOM (Reishi (Ganoderma lucidum) fruiting body double extract)

General ...Orally, reishi mushroom is generally well tolerated.
Most Common Adverse Effects:
Orally: Dizziness, dry mouth, itching, nausea, rash, and stomach upset.

Dermatologic ...Orally, reishi mushroom can cause itching, rash, and other skin reactions (12,5479).

Gastrointestinal ...Orally, reishi mushroom can cause dryness of the mouth, throat, or nasal cavity, nausea, stomach upset, and, more rarely, diarrhea (12,70779,91438,108309).

Hematologic ...Orally, reishi mushroom can cause nosebleed and bloody stools (12,91438).

Hepatic ...One case of hepatotoxicity and one case of fatal fulminant hepatitis have been reported in patients who had used reishi mushroom powder for 1-2 months (70766). There is a case report of a 61-year-old male with hypereosinophilia associated with hepatic nodules following the use of reishi mushroom powder for about 2 months. Symptoms resolved after discontinuation of the product. Although these side effects were thought to be associated with the use of reishi mushroom powder, it is unclear if other factors played a role. The patient had been taking tegafur, gimeracil, and oteracil potassium for about 4 months following anterior resection for rectal adenocarcinoma but discontinued these agents and initiated reishi mushroom due to liver injury (108312).

Neurologic/CNS ...Orally, reishi mushroom can cause dizziness (91438). Other rare symptoms include insomnia and headache (70776,70779).

Pulmonary/Respiratory ...Respiratory allergy to reishi spores can occur (12,5479). Sore throat and runny nose have also been reported (70776,91438).

SHIITAKE MUSHROOM (Shiitake (Lentinus edodes) fruiting body powder)

General ...Orally, shiitake mushroom is generally well tolerated when cooked and consumed as a food.
Most Common Adverse Effects:
Orally: Abdominal discomfort, bloating, diarrhea, nausea, and vomiting.
Serious Adverse Effects (Rare):
Orally: Consumption of raw shiitake mushroom can cause shiitake dermatitis, a skin eruption resembling whiplash marks which can be accompanied by systemic symptoms. Large pieces that have been inadequately chewed can cause intestinal blockage, occasionally requiring surgery.

Dermatologic ...Orally, shiitake mushrooms can cause shiitake dermatitis, a skin eruption that resembles whiplash marks, usually found on the trunk and limbs. This dermatitis is thought to be a toxic response to lentinan or other compounds found normally in uncooked or inadequately cooked shiitake mushroom. The rash can be made worse by scratching. Symptom onset is usually within hours to days and can persist for 3-4 weeks before resolving on its own. There is some evidence that treatment with steroids alone or with antihistamines might reduce the duration of the rash by a small amount in some people (1148,1152,74782,74806,94236,94237,94238,94240,94241,94243) (94244,94246,94247,94248,94249,94252,94253,94254,94255,94256)(94257,94259,94261,94262,108302,111909,111912,111913). The dermatitis may include small purple spots from broken capillaries, skin plaques, burning, blanching, and pustules (94256,108302). Rarely the rash may look like measles rather than whiplash (94256). Histologically, there may be evidence of dermal and epidermal edema, lymphocyte infiltration, and skin thickening (94256,94257). Other symptoms associated with the dermatitis include fever, aching, malaise, eosinophilia, diarrhea, prickling in the hands, trouble swallowing, conjunctivitis, and pustules with small ulcers in the mouth (94240,94246,94247,94249,94256,94257,108302). It is likely that the dermatitis and other symptoms are due to a delayed type hypersensitivity reaction (94244,94255). Cooking shiitake mushroom generally prevents shiitake dermatitis, although some cases have occurred in people who have consumed cooked sources (94242,94244). It appears that to inactivate lentinan, cooking temperatures of at least 130°C are needed (94243).
Less common is a photosensitivity reaction associated with oral ingestion, which involves rash and pruritus after sun exposure (1148,94241).
Orally, the shiitake mushroom extract AHCC has been reported to cause mild itching (30375).

Gastrointestinal ...Orally, shiitake mushrooms can cause abdominal discomfort, including bloating, nausea, pain, vomiting, and diarrhea (1149,30365,30375,30419,94241). Gastrointestinal symptoms, such as diarrhea, problems swallowing, or mouth ulcers have been associated with shiitake dermatitis (94241,94256). Consumption of large pieces of shiitake mushroom with inadequate chewing can cause abdominal obstruction that has resulted in death in one case and surgical intervention in two others. In another case, parenteral nutrition was used exclusively until the shiitake mushroom pieces were passed (1147,94260,103160,108303,108304).
Topically, an oral rinse containing shiitake mushroom extract has been associated with teeth sensitivity, teeth staining, and burning in the mouth (94250).

Hematologic ...Ingestion of shiitake mushroom powder 4 grams daily for 10 weeks caused eosinophilia in 5 of 10 healthy humans (1149). Eosinophilia, and leukocytosis or leukopenia have been reported with shiitake dermatitis (94254,94256,94257).

Immunologic ...Allergic contact dermatitis can occur by contact with shiitake hyphae (filaments) (1153,74785,111913). It appears to be more common in growers or others that handle shiitake mushrooms extensively (94241,94259). Contact or inhalation also results in other symptoms of allergy, such as asthma, rhinitis, conjunctivitis, and pneumonia (94241,94249,94258,94259).

Musculoskeletal ...Orally, the shiitake mushroom extract AHCC has been reported to cause foot cramps and difficulty moving hand joints (30365,30416).

Neurologic/CNS ...In patients experiencing shiitake dermatitis, other symptoms may include prickling in the hands (94256). Malaise has also been reported following oral intake or contact (1151,94240).
Orally, the shiitake mushroom extract AHCC has been reported to cause mild and transient headache (30365).

Ocular/Otic ...Conjunctivitis has been reported rarely in mushroom growers and handlers, or following oral intake in patients with shiitake dermatitis (94241,94256,94259).

Pulmonary/Respiratory ...In mushroom workers, hypersensitivity pneumonitis due to shiitake spore inhalation has occurred. Symptoms include difficulty breathing, chest pain, a dry cough, asthma, and rhinitis (1150,1151,74776,74813,94239,94241,94258,94259).

TURKEY TAIL MUSHROOM (Coriolus (Coriolus versicolor) fruiting body extract)

General ...Orally, turkey tail mushroom and its PSK component are generally well tolerated. There have been reports of gastrointestinal side effects, hematological abnormalities, liver dysfunction, and palpitations, but these are in patients who received PSK in addition to standard chemotherapy. It is not known if these are due to PSK, the chemotherapy, or both.

Cardiovascular ...Palpitations have occurred when PSK is taken with standard chemotherapy for cancer (1657). It is not clear if this is due to PSK, the chemotherapy, or both.

Dermatologic ...Pigmentation of the nails and erythema have occurred when PSK is taken with standard chemotherapy (1657,1660,70175,94076). It is not clear if this is due to PSK, the chemotherapy, or both.
Intravaginally, a specific gel (Papilocare, Procare Health) containing turkey tail mushroom with neem, carboxymethyl-beta-glucan, hyaluronic acid, gotu kola, aloe, and alpha-glucan oligosaccharide has been reported to cause vulvovaginal stinging, burning, itching, and candidiasis (108305,111904). The specific role of turkey tail mushroom is unclear.

Gastrointestinal ...Nausea, vomiting, appetite loss, stomach discomfort, diarrhea, constipation, and gastric ulcer have occurred when PSK is taken with standard chemotherapy for cancer (1651,1657,70175,70201,94076). However, one study reported a decreased incidence of gastrointestinal side effects when PSK was taken with chemotherapy (70188,70197).

Hematologic ...Leukopenia, thrombocytopenia, and albuminuria have occurred when PSK is taken with standard chemotherapy (1651,1657,70175,70201,94076). It is not clear if this is due to PSK, the chemotherapy, or both.

Hepatic ...Elevated liver enzymes, liver function impairment, and hepatotoxicity have occurred when PSK is taken with standard chemotherapy (1651,1657,70175,70201,94076). It is not clear if this is due to PSK, the chemotherapy, or both.

Musculoskeletal ...Malaise and fatigue have occurred when PSK is taken with standard chemotherapy (1657,1660,70175,94076). It is not clear if this is due to PSK, the chemotherapy, or both.

Pulmonary/Respiratory ...Coughing has occurred when PSK is taken with standard chemotherapy (1657,1660,70175,94076). It is not clear if this is due to PSK, the chemotherapy, or both.

VITAMIN C

General ...Orally, intravenously, and topically, vitamin C is well-tolerated.
Most Common Adverse Effects:
Orally: Abdominal cramps, esophagitis, heartburn, headache, osmotic diarrhea, nausea, vomiting. Kidney stones have been reported in those prone to kidney stones. Adverse effects are more likely to occur at doses above the tolerable upper intake level of 2 grams daily.
Topically: Irritation and tingling.
Serious Adverse Effects (Rare):
Orally: There have been rare case reports of carotid inner wall thickening after large doses of vitamin C.
Intravenously: There have been case reports of hyperoxalosis and oxalate nephropathy following high-dose infusions of vitamin C.

Cardiovascular ...Evidence from population research has found that high doses of supplemental vitamin C might not be safe for some people. In postmenopausal adults with diabetes, supplemental vitamin C intake in doses greater than 300 mg per day is associated with increased risk of cardiovascular mortality. However, dietary intake of vitamin C is not associated with this risk. Also, vitamin C intake is not associated with an increased risk of cardiovascular mortality in patients without diabetes (12498).
Oral supplementation with vitamin C has also been associated with an increased rate of carotid inner wall thickening in men. There is preliminary evidence that supplemental intake of vitamin C 500 mg daily for 18 months can cause a 2.5-fold increased rate of carotid inner wall thickening in non-smoking men and a 5-fold increased rate in men who smoked. The men in this study were 40-60 years old (1355). This effect was not associated with vitamin C from dietary sources (1355).
There is also some concern that vitamin C may increase the risk of hypertension in some patients. A meta-analysis of clinical research suggests that, in pregnant patients at risk of pre-eclampsia, oral intake of vitamin C along with vitamin E increases the risk of gestational hypertension (83450). Other clinical research shows that oral intake of vitamin C along with grape seed polyphenols can increase both systolic and diastolic blood pressure in hypertensive patients (13162).

Dental ...Orally, vitamin C, particularly chewable tablets, has been associated with dental erosion (83484).

Dermatologic ...Topically, vitamin C might cause tingling or irritation at the site of application (6166). A liquid containing vitamin C 20%, red raspberry leaf cell culture extract 0.0005%, and vitamin E 1% (Antioxidant and Collagen Booster Serum, Max Biocare Pty Ltd.) has been reported to cause mild tingling and skin tightness (102355). It is unclear if these effects are due to vitamin C, the other ingredients, or the combination.

Gastrointestinal ...Orally, the adverse effects of vitamin C are dose-related and include nausea, vomiting, esophagitis, heartburn, abdominal cramps, gastrointestinal obstruction, and diarrhea. Doses greater than the tolerable upper intake level (UL) of 2000 mg per day can increase the risk of adverse effects such as osmotic diarrhea and severe gastrointestinal upset (3042,4844,96707,104450). Mineral forms of vitamin C, such as calcium ascorbate (Ester-C), seem to cause fewer gastrointestinal adverse effects than regular vitamin C (83358). In a case report, high dose intravenous vitamin C was associated with increased thirst (96709).

Genitourinary ...Orally, vitamin C may cause precipitation of urate, oxalate, or cysteine stones or drugs in the urinary tract (10356). Hyperoxaluria, hyperuricosuria, hematuria, and crystalluria have occurred in people taking 1 gram or more per day (3042,90943). Supplemental vitamin C over 250 mg daily has been associated with higher risk for kidney stones in males. There was no clear association found in females, but the analysis might not have been adequately powered to evaluate this outcome (104029). In people with a history of oxalate kidney stones, supplemental vitamin C 1 gram per day appears to increase kidney stone risk by 40% (12653). A case of hematuria, high urine oxalate excretion, and the presence of a ureteral stone has been reported for a 9-year-old male who had taken about 3 grams of vitamin C daily since 3 years of age. The condition resolved with cessation of vitamin C intake (90936).

Hematologic ...Prolonged use of large amounts of vitamin C can result in increased metabolism of vitamin C; subsequent reduction in vitamin C intake may precipitate the development of scurvy (15). In one case, a patient with septic shock and a large intraperitoneal hematoma developed moderate hemolysis and increased methemoglobin 12 hours after a high-dose vitamin C infusion. The patient received a blood transfusion and the hemolysis resolved spontaneously over 48 hours (112479).

Neurologic/CNS ...Orally, the adverse effects of vitamin C are dose-related and include fatigue, headache, insomnia, and sleepiness (3042,4844,83475,83476).

Renal ...Hyperoxalosis and oxalate nephropathy have been reported following high-dose infusions of vitamin C. Hyperoxalosis and acute kidney failure contributed to the death of a 76-year-old patient with metastatic adenocarcinoma of the lung who received 10 courses of intravenous infusions containing vitamins, including vitamin C and other supplements over a period of 1 month. Dosages of vitamin C were not specified but were presumed to be high-dose (106618). In another case, a 34-year-old patient with a history of kidney transplant and cerebral palsy was found unresponsive during outpatient treatment for a respiratory tract infection. The patient was intubated for acute hypoxemic respiratory failure, initiated on vasopressors, hydrocortisone, and antibacterial therapy, and received 16 doses of vitamin C 1.5 grams. Serum creatinine level peaked at greater than 3 times baseline and the patient required hemodialysis for oliguria and uncontrolled acidosis. Kidney biopsy revealed oxalate nephropathy with concomitant drug-induced interstitial nephritis (106625). In another case, a 41-year-old patient with a history of kidney transplant presented with fever, nausea, and decreased urine output 4 days after receiving intravenous vitamin C 7 grams for urothelial carcinoma. Serum creatinine levels increased from 1.7 mg/dL to 7.3 mg/dL over those 4 days, and hemodialysis was initiated 3 days after admission due to anuria. Renal biopsy confirmed the diagnosis of acute oxalate nephropathy (109962).

Other ...Intravenously, hypernatremia and falsely elevated ketone levels is reported in a patient with septic shock and chronic kidney disease after a high-dose vitamin C infusion. The hypernatremia resolved over 24 hours after cessation of the infusion (112479).

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