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LIKELY EFFECTIVE

• Chromium deficiency. Oral or parenteral chromium is effective for the treatment and prevention of chromium deficiency. Details: Chromium is effective for preventing and treating symptoms of chromium deficiency, including hyperglycemia, glycosuria, sudden weight loss, peripheral neuropathy, and confusion (7135).

POSSIBLY EFFECTIVE

• Diabetes. Oral chromium seems to be modestly beneficial for improving glycemic control in diabetes, especially when used in doses greater than 200 mcg daily and in patients with poorly controlled diabetes. It is unclear if chromium helps to prevent the development of diabetes. Details: Epidemiological research has found that lower toenail chromium levels are associated with an increased risk of diabetes and cardiovascular disease (11908). In 2005, the US Food and Drug Administration (FDA) allowed a qualified health claim stating that chromium picolinate may reduce the risk of type 2 diabetes. However, the FDA has determined that any relationship between chromium picolinate and type 2 diabetes is highly uncertain and is based on limited scientific evidence (102362). Research on the use of chromium for the treatment of type 2 diabetes is conflicting but seems to show modest benefit in some patients. Several clinical studies, most including fewer than 80 patients with type 2 diabetes, show that taking chromium decreases fasting blood glucose, postprandial glucose, insulin, and glycated hemoglobin (HbA1c) levels and increases insulin sensitivity (6867,7137,12390,14440,15169,42628,42638,95097,103745). However, other small clinical studies show that chromium is no better than placebo for improving most glycemic indices in patients with diabetes (7060,14325,42679,42707,90059,103746,103749). Some of these studies may not have been adequately powered and some had a high risk of bias. Furthermore, these studies had high heterogeneity related to study population and size, chromium supplementation duration, formulation, and dose, and accepted standards of diabetes care. Multiple meta-analyses pooling results of these small clinical trials also show mixed results (90055,90063,95098,105026,110610,111420). The most recent of the aforementioned meta-analyses show that chromium picolinate lowers HbA1c by about 0.6%, with conflicting findings related to fasting blood glucose and measures of insulin resistance (110610,111420). It is unclear if chromium yeast, chromium dinicocysteinate, or chromium with biotin or other natural ingredients are beneficial. Chromium seems to be most beneficial in doses of greater than 200 mcg taken for 12 weeks or longer, and in patients with poorly controlled diabetes with a baseline HbA1c of 8% or greater (90063,105026). There is also speculation that chromium might primarily benefit patients with low chromium levels; however, there has not been an analysis specifically evaluating this population (6867,7058,13725,14325,95098). Some research suggests that chromium might also modestly improve lipid levels in patients with type 2 diabetes (1934,6867,95098). A meta-analysis of clinical trials in patients with type 2 diabetes shows that taking chromium 42-1000 mcg daily for 5-26 weeks decreases triglyceride levels by 7 mg/dL and increases high-density lipoprotein cholesterol levels by 2 mg/dL when compared with control. Taking chromium did not affect low-density lipoprotein cholesterol levels. However, the validity of these results is limited by high heterogeneity (110605). Another meta-analysis failed to demonstrate any effects of chromium on lipid levels (110610). Research on chromium's effect on blood pressure in patients with type 2 diabetes is mixed. A meta-analysis of clinical trials in patients with type 2 diabetes shows that taking chromium 200-1000 mcg daily for 8-25 weeks lowers diastolic blood pressure by 2 mmHg, but does not improve systolic blood pressure or body mass index, when compared with placebo (110607). Preliminary clinical research shows that chromium picolinate might improve metabolic parameters in patients with other forms of diabetes as well. This includes those with type 1 diabetes (1935), diabetes secondary to corticosteroid use (5039,42829), and gestational diabetes (42817).

POSSIBLY INEFFECTIVE

• Hypertension. Meta-analyses of small clinical trials suggest that oral chromium does not lower blood pressure by a clinically meaningful amount. Details: A meta-analysis of randomized clinical trials in adults with different metabolic disorders shows that taking chromium 42-1000 mcg daily for 12-24 weeks does not lower systolic or diastolic blood pressure when compared with placebo (110609). A meta-analysis of randomized clinical trials in adults with different chronic disorders shows that taking chromium 42-1000 mcg daily for 4-25 weeks lowers systolic and diastolic blood pressure by 3 mmHg and 1 mmHg, respectively, when compared with placebo. However, the validity of this meta-analysis is limited by high heterogeneity (110604). Another meta-analysis of randomized clinical trials including patients with type 2 diabetes shows that taking chromium 200-1000 mcg daily for 8-25 weeks lowers diastolic blood pressure by 2 mmHg, but not systolic blood pressure, when compared with placebo (110607). In addition, the validity of these results is limited by inclusion of patients with and without hypertension at baseline (110604,110607,110609).
• Impaired glucose tolerance (Prediabetes). Oral chromium does not seem to improve glycemic indices in patients with prediabetes. Details: Some clinical research shows that adults with impaired glucose tolerance do not have improved glycemic parameters or insulin sensitivity after taking chromium picolinate 500-1000 mcg daily for up to 6 months when compared with placebo (13053,42670). Likewise, a small clinical study in elderly patients with impaired glucose tolerance shows that chromium supplements do not improve glucose tolerance or triglyceride or cholesterol levels when compared with placebo (13722). Finally, a preliminary clinical study in overweight or obese adults with prediabetes shows that taking two capsules of a combination product containing chromium, cinnamon, and carnosine (Glycabiane, PiLeJe) daily for 4 months decreases fasting plasma glucose by approximately 4 mg/dL when compared with placebo, but does not improve fasting plasma insulin, measures of insulin sensitivity or resistance, or glycated hemoglobin (HbA1C) (94234). The small effect on fasting plasma glucose is clinically insignificant and may be due to the other ingredients in this product.
• Schizophrenia. Oral chromium does not seem to improve psychological measures in patients with schizophrenia. Details: Clinical research in patients with schizophrenia shows that taking chromium polynicotinate 400 mcg daily for 3 months does not affect weight or mental status when compared with placebo (42613).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Antiretroviral-induced insulin resistance. It is unclear if oral chromium is beneficial for preventing antiretroviral-induced insulin resistance. Details: Preliminary clinical research in patients with HIV treated with highly active antiretroviral therapy (HAART) shows that taking chromium nicotinate 200 mcg or chromium picolinate 1000 mcg daily for 8-16 weeks may help decrease insulin resistance and increase glucose disposal when compared to baseline (42630,42662). The validity of this finding is limited by the lack of a control group.
• Athletic performance. It is unclear if chromium enhances athletic performance, although some research suggests that it may improve body composition when used in conjunction with exercise. Details: One large clinical study shows taking chromium 400 mcg daily, in conjunction with resistance training, can increase weight loss, body fat loss, and lean body mass when compared with placebo in conjunction with resistance training (6868). However, other, very small clinical studies show that adding chromium picolinate or chromium chloride 177-400 mcg daily to a weight-training program does not improve body composition when compared with weight-training alone (6860,6861,6862,42747). These studies may not have been adequately powered to detect a difference in outcomes.
• Atypical depression. It is unclear if oral chromium is beneficial in patients with atypical depression. Details: Preliminary clinical research in patients with atypical depression shows that taking chromium picolinate 400 mcg daily for 2 weeks followed by 600 mcg daily for an additional 6 weeks improves response and remission rates when compared with placebo (10309). However, other clinical research shows that taking elemental chromium 400 mcg in the form of chromium picolinate daily for 2 weeks followed by 600 mcg daily for an additional 6 weeks does not improve most symptoms of atypical depression, although appetite and sexual drive may improve, when compared with placebo (42600).
• Beta blocker-induced dyslipidemia. It is unclear if oral chromium is beneficial in patients with dyslipidemia due to beta-blocker use. Details: One small clinical study in patients who take beta-blockers shows that taking glucose tolerance factor (GTF)-chromium 600 mcg daily for 2 months increases high-density lipoprotein (HDL) cholesterol levels by 16%, but does not affect other lipid parameters, when compared with placebo (5040).
• Binge eating disorder. It is unclear if oral chromium is beneficial in patients with binge eating disorder. Details: One small clinical study in adults with overweight and binge eating disorder shows that taking chromium picolinate 600 or 1000 mcg daily for 6 months does not affect binge eating frequency, body weight, or depressive symptoms when compared with placebo (90057).
• Bipolar disorder. It is unclear if oral chromium is beneficial in patients with treatment-resistant bipolar disorder. Details: Preliminary clinical research in patients with treatment-resistant, rapid-cycling bipolar disorder shows that taking chromium chloride (Hypo-A Chrom, Hypo-A GmbH) 600-800 mcg daily for up to 2 years can decrease the frequency of affective episodes by approximately three episodes annually when compared to baseline (42618). The validity of this finding is limited by the lack of a control group.
• Cognitive impairment. It is unclear if oral chromium prevents or treats cognitive impairment. Details: Some clinical research shows that taking chromium picolinate standardized to contain elemental chromium 1000 mcg daily for 12 weeks does not improve memory or depression in elderly patients with mild cognitive impairment when compared with placebo. However, results from neuroimaging scans suggest that chromium increases the activity of certain regions of the brain during memory tasks when compared with placebo (42666).
• Hyperlipidemia. Small clinical studies suggest that oral chromium may modestly reduce lipid levels in patients with hyperlipidemia. Details: One small clinical study in patients with atherosclerotic disease shows that taking chromium 250 mcg as chromium chloride daily for 7-16 months decreases triglycerides and increases high-density lipoprotein (HDL) cholesterol, but not other lipid parameters, when compared with placebo (7060). Other small clinical studies in adults with hyperlipidemia show that taking chromium picolinate 200 mcg daily for 6 weeks, chromium polynicotinate 200 mcg twice daily, or brewer's yeast containing 48 mcg elemental chromium daily for 6-8 weeks decrease total and low-density lipoprotein (LDL) cholesterol when compared to baseline (37178,42585,42710). The validity of this finding is limited by the lack of comparison with a control group. A meta-analysis of small heterogeneous clinical studies in patients mostly without hyperlipidemia shows that taking chromium does not affect lipid levels when compared with placebo (105029). A meta-analysis of randomized clinical trials including patients with type 2 diabetes shows that taking chromium 42-1000 mcg daily for 5-26 weeks modestly improves triglyceride and HDL cholesterol levels, but not LDL cholesterol levels, when compared with control. However, the validity of these results is limited by high heterogeneity and inclusion of patients with and without hyperlipidemia (110605). In addition, some meta-analyses have failed to demonstrate any effects of chromium on lipid levels in adults with diabetes (110610). Limited research has tested high-dose chromium in children. One small clinical study in children with hypercholesterolemia shows that taking chromium polynicotinate 400-600 mcg with glucomannan 1000-1500 mg twice daily for 8 weeks reduces total and LDL cholesterol when compared to baseline (90061). It is unclear if this effect is due to chromium, glucomannan, or the combination.
• Hypoglycemia. It is unclear if oral chromium helps to reverse or prevent hypoglycemia. Details: One very small clinical study in patients with reactive hypoglycemia shows that taking chromium chloride 200 mcg daily for 3 months increases blood glucose levels and improves insulin binding and hypoglycemic symptoms following an oral glucose load (6859). Another small clinical study in patients with symptomatic hypoglycemia shows that taking chromium yeast (Biochrome, Pharma-Nord) 125 mcg daily for 3 months improves symptoms, including chilliness, trembling, and disorientation, when compared with baseline (42711). The validity of this finding is limited by the lack of a control group.
• Metabolic syndrome. It is unclear if oral chromium is beneficial in patients with metabolic syndrome. Details: One small clinical study in patients with metabolic syndrome shows that taking a particular chromium picolinate product (Chromax, Nutrition 21) 500 mcg twice daily for 16 weeks does not affect weight, waist circumference, insulin sensitivity, glycated hemoglobin (HbA1C), or lipid levels when compared with placebo (42654).
• Myocardial infarction (MI). It is unclear if oral chromium helps to prevent MI. Details: Epidemiological research has found that low toenail chromium concentrations are associated with an increased risk of MI (13728). However, toenail chromium concentrations might not be a reliable predictor of body stores of chromium. There is also no reliable research showing that chromium supplements can prevent MI.
• Nonalcoholic fatty liver disease (NAFLD). It is unclear if oral chromium slows NAFLD progression. Details: One small clinical study in patients with NAFLD shows that taking chromium picolinate 200 mcg two times daily after meals for 12 weeks does not affect liver enzyme levels or body weight when compared with placebo (105027).
• Obesity. Although some research suggests that oral chromium may increase weight loss, this increase in weight loss is not likely to be considered clinically relevant. Details: Meta-analyses of clinical studies in adults with overweight or obesity show that taking chromium picolinate 200-1000 mcg daily for 12-16 weeks might result in a cumulative weight loss of about 0.5-1 kg when compared with placebo (90062,90065). However, this small reduction in weight is unlikely to be considered clinically significant. Additionally, small clinical studies in healthy adults and children with overweight or obesity show that taking oral chromium 200-1000 mcg daily for 6-24 weeks does not reduce weight when compared with control (6860,13727,17224,42680). Some of these studies may not have been adequately powered to detect a smaller effect. A meta-analysis of randomized clinical trials among adults with type 2 diabetes shows that taking chromium 200-1000 mcg daily for 8-25 weeks does not lower body mass index when compared with placebo. However, the validity of these results is limited by inclusion of patients with and without obesity at baseline (110607).
• Polycystic ovary syndrome (PCOS). It is unclear if oral chromium improves symptoms of PCOS. Details: One small clinical study in patients with PCOS shows that taking chromium picolinate 1000 mcg daily for 6 months along with diet and exercise counseling decreases body mass index and improves rates of ovulation and regular menstruation when compared with placebo (95094). Also, some clinical research shows that taking chromium picolinate (21st Century HealthCare, Inc. or Nature Made) 200 mcg daily for 8 weeks increases insulin sensitivity when compared with placebo (95095,98687). However, other preliminary clinical research shows that taking chromium picolinate 200 mcg daily for 4 months does not affect insulin sensitivity or improve ovulation rates (42603). Although chromium picolinate at doses of less than 1000 mcg might have very small effects on fasting glucose, these doses do not seem to have clinically beneficial effects on fasting glucose, pregnancy rate, or testosterone levels (95094,95095,98687). A lower dose of chromium has also been studied in combination with carnitine. One small clinical study in adults with overweight and PCOS shows that taking chromium picolinate 200 mcg daily with carnitine 1000 mg daily for 12 weeks modestly reduces fasting blood glucose, insulin resistance, and body weight, and slightly increases insulin sensitivity, when compared with placebo (103747). However, it is unclear if this benefit is clinically significant. Additionally, it is unclear if these effects are due to chromium, carnitine, or the combination. Carnitine has demonstrated clinical benefit when used alone in PCOS.
• Turner syndrome. It is unclear if oral chromium is beneficial in patients with this condition. Details: A small clinical study shows that taking brewer's yeast 30 grams containing chromium 50 mcg daily for 8 weeks might improve abnormalities in glucose and lipid metabolism when compared with baseline in patients with Turner syndrome, a genetic disorder that has a high incidence of diabetes (13729). The validity of this finding is limited by the lack of a comparator group. More evidence is needed to rate chromium for these uses.

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INSUFFICIENT RELIABLE EVIDENCE to RATE

• Diabetes. It is unclear if oral gymnema is beneficial for diabetes. Details: A meta-analysis of 10 small clinical studies in adults with type 2 diabetes shows that taking gymnema modestly reduces fasting and postprandial blood glucose levels, and also seems to reduce glycated hemoglobin (HbA1c), when compared to baseline. Gymnema may also modestly reduce total cholesterol and triglyceride levels. (110022). Another meta-analysis of 6 small clinical studies, that includes some of the same studies, also shows that taking gymnema modestly reduces fasting blood glucose, total cholesterol, and triglyceride levels when compared with diet or placebo. However, this analysis shows that gymnema does not improve HbA1c, oral glucose tolerance, or low-density lipoprotein cholesterol (112184). The validity of these analyses is limited by the inclusion of mostly low-quality studies that enrolled heterogeneous patient populations and employed varying gymnema dosing regimens of 0.4-10 grams daily, sometimes in conjunction with antidiabetes medications. In addition, many of the included studies were non-randomized and lacked a comparator group.
• Impaired glucose tolerance (prediabetes). It is unclear if oral gymnema is beneficial for impaired glucose tolerance. Details: One small clinical study in overweight or obese patients with impaired glucose tolerance shows that taking gymnema (Swanson Superior Herbs) 300 mg twice daily for 12 weeks does not improve glucose control, lipid profile, anthropometric indices, or blood pressure when compared with placebo (105346). However, this study may have been inadequately powered to detect a difference between groups.
• Metabolic syndrome. It is unclear if oral gymnema is beneficial for metabolic syndrome. Details: One small clinical study shows that taking gymnema leaf (Swanson Premium G. sylvestre leaf, Swanson Health Products) 300 mg twice daily for 12 weeks reduces body weight by 4% and body mass index (BMI) by 2% when compared to baseline in overweight adults with metabolic syndrome. However, it is unclear if these changes are significant when compared with placebo. In addition, gymnema does not appear to improve blood glucose levels, insulin sensitivity, or blood lipid levels when compared with placebo (96235).
• Obesity. It is unclear if oral gymnema improves weight loss in overweight or obese adults. Details: One small clinical study shows that taking gymnema leaf (Swanson Premium G. sylvestre leaf, Swanson Health Products) 300 mg twice daily for 12 weeks modestly reduces body weight and body mass index (BMI) when compared to baseline in overweight adults with metabolic syndrome. However, it is unclear if these changes are significant when compared with placebo (96235). Another small clinical study by the same authors evaluating overweight adults with impaired glucose tolerance shows that taking gymnema (Swanson Superior Herbs) 300 mg twice daily for 12 weeks does not reduce body weight or BMI when compared with placebo (105346). Gymnema has also been studied in combination with other ingredients. One small clinical study shows that taking a combination of gymnema extract 400 mg, hydroxycitric acid 2800 mg, and niacin-bound chromium 4 mg orally daily for 8 weeks decreases BMI and body weight when compared to baseline in overweight and obese adults. This product provided 400 mcg of elemental chromium and 100 mg of gymnemic acids (42604). It is unclear if these effects are due to gymnema, other ingredients, or the combination. More evidence is needed to rate gymnema for these uses.

(Read more about GYMNEMA)

POSSIBLY EFFECTIVE

• Obesity. Oral Phaseolus vulgaris extract may reduce body weight and waist circumference in overweight and obese adults. Details: A meta-analysis of 6 small clinical studies shows that taking Phaseolus vulgaris extract daily for 4-12 weeks reduces body weight by around 1.6% when compared with placebo (107439). While some small studies show conflicting findings (12186,26158), most research in overweight and obese adults suggests that taking white kidney bean extract 800-1000 mg or cranberry bean extract 100 mg three times daily for 5-12 weeks reduces body weight by 1.5-4 kg, body mass index by about 0.7 kg/m2, and waist circumference by about 1.5-5 cm when compared with placebo or other control (26156,29926,93075,93077,104875). Specific products evaluated include Phase 2 (Pharmachem Labs; also marketed as Starchlite and Phaselite) (26156,29926); Carb Intercept with Phase 2 (Natrol LLC) (93075); and Beanblock (Indena S.p.A) (93077). Phaseolus vulgaris extract has also been evaluated in combination with other ingredients, with modestly positive results. These combination products include Blokcal (Pharmachem Labs) containing white kidney bean extract (Phase 2, Pharmachem Labs) 445 mg daily and elemental chromium 50-60 mcg daily for 30 days (15518); Suco-Bloc (Med-Eq), containing white kidney bean extract (Phaseolamin, Leuven Bioproducts) 200 mg, inulin from chicory root (Raftiline, Orafti SA) 200 mg, and garcinia extract 50 mg per tablet, 2 tablets three times daily with meals for 12 weeks (26157); Phaseolamin 1600 diet (Metabolic Inc.), containing the Phaseolus vulgaris constituent phaseolamin 750 mg with clove 200 mg, lysine 20 mg, arginine 20 mg, and alanine 20 mg, taken in two divided doses daily for 8 weeks (93076); and Bonvit (Indena), containing Phaseolus vulgaris extract 100 mg and artichoke 200 mg three times daily for 8 weeks (93080).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Colorectal cancer. It is unclear if oral Phaseolus vulgaris is beneficial for the prevention of colorectal cancer recurrence. Details: Observational research has found that dietary intake of several varieties of Phaseolus vulgaris, including baked beans, kidney beans, pinto beans, lima beans, and navy beans, is inversely associated with the risk of advanced colorectal adenoma recurrence. Results from the study show that the odds for advanced adenoma recurrence is 65% lower for patients who consume higher amounts of Phaseolus vulgaris when compared with those who consume lower amounts (29922).
• Diabetes. Small clinical studies suggest that oral Phaseolus vulgaris may not improve postprandial glucose levels in patients with type 2 diabetes. Details: While results from some small clinical studies in patients with type 2 diabetes suggest that taking Phaseolus vulgaris extract or consuming Phaseolus vulgaris beans can reduce postprandial glucose levels, most studies, including a meta-analysis of 6 small clinical trials, show that Phaseolus vulgaris does not significantly reduce postprandial glucose when compared with placebo or other control (93078,107439). Another small clinical study in patients with type 2 diabetes shows that taking 15 grams of a combination of Phaseolus vulgaris pod, white mulberry, and bilberry three times daily for 2 months decreases blood glucose by up to 24% when compared with baseline (33943). It is unclear if these findings are due to Phaseolus vulgaris, other ingredients, or the combination. Additionally, the validity of these findings is limited by the lack of a control group.
• Hypercholesterolemia. Oral Phaseolus vulgaris has only been evaluated in combination with other ingredients; its effect when used alone is unclear. Details: One small, open-label clinical study in overweight and obese patients shows that taking Phaseolus vulgaris (white kidney bean) extract 300-600 mg plus carob gum extract 50-100 mg three times daily for 3-9 months modestly reduces total cholesterol levels and increases excretion of fat in the feces when compared to baseline (10633). The validity of these findings is limited by the lack of a comparator group.
• Kidney stones (nephrolithiasis). It is unclear if oral Phaseolus vulgaris extract is beneficial in patients with kidney stones. Details: A small clinical study in adults with small kidney stones shows that taking a Phaseolus vulgaris extract made from 250 grams of green beans three times a week for 6 weeks modestly reduces the size of kidney stones and lowers urinary calcium and oxalate levels when compared with a control group (104874).
• Lung cancer. It is unclear if oral Phaseolus vulgaris is beneficial for the prevention of lung cancer. Details: Observational research has found that consuming higher amounts of dietary phytoestrogens, such as isoflavones from Phaseolus vulgaris beans and soy, is associated with a 44% to 72% lower risk of developing lung cancer when compared with consuming lower amounts. The beneficial effect appears to be more pronounced in males than females (13190).
• Myocardial infarction (MI). Although there has been interest in using oral Phaseolus vulgaris for the prevention of MI, there is insufficient reliable information about the clinical effects of Phaseolus vulgaris for this purpose.
• Urinary tract infections (UTIs). Although there has been interest in using oral Phaseolus vulgaris for UTIs, there is insufficient reliable information about the clinical effects of Phaseolus vulgaris for this purpose. More evidence is needed to rate Phaseolus vulgaris for these uses.

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LIKELY EFFECTIVE

• Vanadium deficiency. Oral vanadium is effective for the prevention of vanadium deficiency. Details: Taking vanadium is effective for preventing vanadium deficiency (7135).

INSUFFICIENT RELIABLE EVIDENCE to RATE

• Athletic performance. Although there has been interest in using oral vanadium for improving athletic performance, there is insufficient reliable information about the clinical effects of vanadium for this purpose.
• Cancer. Although there has been interest in using oral vanadium for cancer, there is insufficient reliable information about the clinical effects of vanadium for this purpose.
• Diabetes. Small clinical studies suggest that high doses of oral vanadium may improve insulin sensitivity in patients with type 2 diabetes; however, these high doses may be unsafe. It is unclear if lower doses of vanadium have the same effects. Details: Five very small clinical studies including fewer than 40 patients with type 2 diabetes show that taking high oral doses of vanadyl sulfate (50-75 mg twice daily; 31-46 mg elemental vanadium daily) for up to 6 weeks can improve hepatic and peripheral insulin sensitivity and might reduce blood glucose levels when compared to baseline (3055,3056,3057,12557,12558). However, prolonged use of these high doses might not be safe (7135). It is not known if lower doses have the same benefit.
• Hyperlipidemia. Although there has been interest in using oral vanadium for hyperlipidemia, there is insufficient reliable information about the clinical effects of vanadium for this purpose.
• Impaired glucose tolerance (prediabetes). It is unclear if oral vanadium is beneficial in patients with impaired glucose tolerance. Details: A very small clinical study in overweight or obese adults with impaired glucose tolerance shows that taking vanadyl sulfate 50 mg twice daily for 30 days does not improve insulin sensitivity or glucose metabolism when compared with placebo (92819).
• Tuberculosis. Although there has been interest in using oral vanadium for tuberculosis, there is insufficient reliable information about the clinical effects of vanadium for this purpose. More evidence is needed to rate vanadium for these uses.

(Read more about VANADIUM)

LIKELY SAFE ...when used orally and appropriately in medicinal amounts, short-term. Chromium has been safely used in doses up to 1000 mcg daily for up to 6 months (1934,5039,5040,6858,6859,6860,6861,6862,6867,6868)(7135,7137,10309,13053,14325,14440,17224,90057,90061)(90063,94234,95095,95096,95097,98687); however, most of these studies have used chromium doses in a range of 150-600 mcg. The Food and Drug Administration (FDA) and Institute of Medicine (IOM) evaluations of the safety of chromium suggest that it is safe when used in doses of 200 mcg daily for up to 6 months (13241,13242).

POSSIBLY SAFE ...when used orally and appropriately in medicinal amounts, long-term. Chromium has been safely used in a small number of studies at doses of 200-1000 mcg daily for up to 2 years (7060,7135,42618,42628,42666,110605,110607,110609). However, the Food and Drug Administration (FDA) and Institute of Medicine (IOM) evaluations of the safety of chromium suggest that it is safe when used in doses of 200 mcg daily for up to 6 months (13241,13242).

CHILDREN: LIKELY SAFE
when used orally and appropriately in amounts not exceeding the daily adequate intake (AI) levels by age: 0-6 months, 0. 2 mcg; 7-12 months, 5.5 mcg; 1-3 years, 11 mcg; 4-8 years, 15 mcg; males 9-13 years, 25 mcg; males 14-18 years, 35 mcg; females 9-13 years, 21 mcg; females 14-18 years, 24 mcg (7135). POSSIBLY SAFE...when used orally and appropriately in amounts exceeding AI levels. Chromium 400 mcg daily has been used safely for up to 6 weeks (42680).

PREGNANCY: LIKELY SAFE
when used orally and appropriately in amounts not exceeding adequate intake (AI) levels. The AI for pregnancy is 28 mcg daily for those 14-18 years of age and 30 mcg daily for those 19-50 years of age (7135).

PREGNANCY: POSSIBLY SAFE
when used orally in amounts exceeding the adequate intake (AI) levels. There is some evidence that patients with gestational diabetes can safely use chromium in doses of 4-8 mcg/kg (1953); however, patients should not take chromium supplements during pregnancy without medical supervision.

LACTATION: LIKELY SAFE
when used orally and appropriately in amounts not exceeding adequate intake (AI) levels. The AI for lactation is 44 mcg daily for those 14-18 years of age and 45 mcg daily for those 19-50 years of age (7135). Chromium supplements do not seem to increase normal chromium concentration in human breast milk (1937). There is insufficient reliable information available about the safety of chromium when used in higher amounts while breast-feeding.

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POSSIBLY SAFE ...when used orally and appropriately. Gymnema leaf extract has been used safely in doses of 200 mg twice daily for up to 20 months or 300 mg twice daily for 12 weeks (45,46,42604,105346).

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

(Read more about GYMNEMA)

POSSIBLY SAFE ...when used orally and appropriately. Most research has evaluated a specific Phaseolus vulgaris (white kidney bean) extract (Phase 2, Pharmachem Labs), which appears to be safe in doses of up to 3 grams daily for 2-3 months (12186,15518,26157,29926). Other Phaseolus vulgaris (white kidney bean) extracts also seem to be safe in doses of 0.9-2.4 grams daily when used for up to 3 months (10633,104875).

POSSIBLY UNSAFE ...when large amounts of fresh Phaseolus vulgaris husks are ingested. Raw Phaseolus vulgaris husks contain lectins that can cause gastrointestinal upset. Cooking destroys the lectins (18).

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

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LIKELY SAFE ...when used orally and appropriately. Vanadium is safe when taken in amounts below the tolerable upper intake level (UL) of 1.8 mg daily (7135).

POSSIBLY UNSAFE ...when used orally in high doses. Taking more than the tolerable upper intake level (UL) of 1.8 mg daily can increase the risk of gastrointestinal side effects and theoretically, kidney toxicity (7135). In some cases, patients with diabetes have used very high doses (100 mg daily) safely for up to 4 weeks (3055,3056,3057). However, there is concern that prolonged use of high doses might cause serious side effects including kidney damage (7135). Doses of 22.5 mg daily for five months can cause cramps and diarrhea (3012).

CHILDREN: LIKELY SAFE
when used orally in amounts found in foods (7135). There is insufficient reliable information available about the safety of vanadium when used in amounts greater than those typically found in foods.

PREGNANCY: LIKELY SAFE
when used orally in amounts found in foods (7135).

PREGNANCY: POSSIBLY UNSAFE
when used orally in medicinal amounts. Epidemiological research has found that increased urinary levels of vanadium are associated with an increased risk of both term and preterm premature rupture of membranes (PROM). When comparing tertiles of urinary vanadium levels, patients in the middle tertile had 1.66 times the risk of term PROM when compared with the lowest tertile, and those in the highest tertile had 3.75 times the risk. For preterm PROM (rupture prior to 37 weeks' gestation), those in the highest tertile had an 8.14 times increased risk when compared with those in the lowest tertile (99052). Epidemiological research has also found that higher prenatal serum levels of vanadium are associated with impaired fetal growth, particularly in male newborns. The risk appears greatest with vanadium exposure in the second trimester (102096).

LACTATION: LIKELY SAFE
when used orally in amounts found in foods (7135). There is insufficient reliable information available about the safety of vanadium when used in amounts greater than those typically found in foods; avoid using.

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ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = A Theoretically, chromium may have additive effects with antidiabetic agents and increase the risk of hypoglycemia.  Details Some research shows that taking chromium might lower blood glucose levels, especially in patients with poorly controlled type 2 diabetes (7137,14440,15169,94234,95097,95098,98687).

ASPIRIN Interaction Rating = Minor Be watchful with this combination. Severity = Insignificant •  Occurrence = Possible •  Level of Evidence = D Theoretically, aspirin might increase chromium absorption.  Details Animal research suggests that aspirin may increase chromium absorption and chromium levels in the blood (21055).

INSULIN Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = B Theoretically, concomitant use of chromium and insulin might increase the risk of hypoglycemia.  Details In clinical research, chromium has been shown to increase insulin sensitivity (1952,14440,95095),

LEVOTHYROXINE (Synthroid, others) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Chromium might bind levothyroxine in the intestinal tract and decrease levothyroxine absorption.  Details Clinical research in healthy volunteers shows that taking chromium picolinate 1000 mcg with levothyroxine 1 mg decreases serum levels of levothyroxine by 17% when compared to taking levothyroxine alone (16012). Advise patients to take levothyroxine at least 30 minutes before or 3-4 hours after taking chromium.

NONSTEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDs) Interaction Rating = Minor Be watchful with this combination. Severity = Mild •  Occurrence = Possible •  Level of Evidence = D NSAIDs might increase chromium levels in the body.  Details Drugs that are prostaglandin inhibitors, such as NSAIDs, seem to increase chromium absorption and retention (7135).

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ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, taking gymnema with antidiabetes drugs might increase the risk of hypoglycemia.  Details Gymnema reduces blood glucose levels in some human and animal research. In human studies, it has been shown to enhance the blood glucose lowering effects of hypoglycemic drugs (45,46,92119,92121,92123). However, other research in adults with prediabetes or metabolic syndrome suggests that gymnema does not reduce fasting levels of blood glucose (96235,105346). Until more is known, monitor blood glucose levels closely.

CYTOCHROME P450 1A2 (CYP1A2) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, gymnema might increase levels of drugs metabolized by CYP1A2.  Details Animal and in vitro research shows that gymnema can inhibit the CYP1A2 enzyme (96236,96237,96238). In one animal study, oral administration of gymnema for 7 days increased the plasma concentrations of phenacetin, a CYP1A2 substrate, by about 1.4-fold and reduced the clearance of phenacetin by about 29% (96237).

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, gymnema might increase or decrease levels of drugs metabolized by CYP2C9.  Details Animal research shows that gymnema can induce the CYP2C9 enzyme. In one animal study, gymnema caused a 2.4-fold increase in the clearance of tolbutamide, a CYP2C9 substrate, in rats (96237). In vitro research also shows that gymnema can inhibit CYP2C9 (96236,96238).

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES Interaction Rating = Minor Be watchful with this combination. Severity = Moderate •  Occurrence = Unlikely •  Level of Evidence = D Theoretically, gymnema might increase levels of drugs metabolized by CYP3A4.  Details One in vitro study using rat liver microsomes shows that gymnema can modestly inhibit the CYP3A4 enzyme (96238). However, other in vitro research using human liver microsomes shows that gymnema does not affect CYP3A4 activity (96236). Animal research also shows that gymnema does not alter the function of CYP3A4. In one study in rats, oral administration of gymnema for 7 days did not alter the clearance of amlodipine, a CYP3A4 substrate (96237).

PHENACETIN Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking gymnema with phenacetin might increase the levels of phenacetin.  Details Animal research shows that gymnema, administered orally for 7 days, decreases the clearance of phenacetin in a dose-dependent manner by about 21% to 29% and increases plasma levels about 1.3- to 1.4-fold when compared to control (96237,96238).

TOLBUTAMIDE (Orinase) Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, taking gymnema with tolbutamide might the decrease levels of tolbutamide.  Details Animal research shows that gymnema, administered orally for 7 days, increases the clearance of tolbutamide by 2.4-fold when compared to control (96237).

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ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Possible •  Level of Evidence = D Theoretically, Phaseolus vulgaris might increase the risk of hypoglycemia when taken with antidiabetes drugs.  Details Small clinical studies suggest that Phaseolus vulgaris beans or bean pods, ingested alone or along with white mulberry leaf and bilberry, reduce blood glucose levels in some patients with diabetes (29921,29925,33943).

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ANTICOAGULANT/ANTIPLATELET DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = High •  Occurrence = Possible •  Level of Evidence = D Theoretically, vanadium might increase the risk of bleeding when taken with anticoagulant/antiplatelet drugs.  Details In vitro research shows that the sodium orthovanadate form of vanadium prolongs clotting time, likely through inhibition of thrombin and factor Xa (3054).

ANTIDIABETES DRUGS Interaction Rating = Moderate Be cautious with this combination. Severity = Moderate •  Occurrence = Probable •  Level of Evidence = B Theoretically, vanadium might increase the risk of hypoglycemia when taken with antidiabetes drugs.  Details A few very small clinical studies in patients with type 2 diabetes show that the vanadyl sulfate form of vanadium increases insulin sensitivity (3055,3056,3057) and might lower blood glucose levels (3057).

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General ...Orally, chromium is generally well tolerated.
Most Common Adverse Effects:
Orally: Gastrointestinal irritation, headaches, insomnia, irritability, mood changes.
Serious Adverse Effects (Rare):
Orally: Rare cases of kidney and liver damage, rhabdomyolysis, and thrombocytopenia have been reported.

Dermatologic ...Orally, chromium-containing supplements may cause acute generalized exanthematous pustulosis (42561), skin rashes (42679), and urticaria (17224). Also, chromium picolinate or chromium chloride may cause systemic contact dermatitis when taken orally, especially in patients with contact allergy to chromium (6624,90058). In one clinical study, a patient taking chromium nicotinate 50 mcg daily reported itchy palms that improved after the intervention was discontinued. It is unclear of this effect was due to the chromium or another factor (95096).
Topically, hexavalent chromium, which can be present in some cement, leather products, or contaminated soil, may cause allergic contact dermatitis (42645,42789,90060,90064,110606).
A case of lichen planus has been reported for a patient following long-term occupational exposure to chromium (42688).

Endocrine ...Orally, cases of hypoglycemia have been reported for patients taking chromium picolinate 200-1000 mcg daily alone or 200-300 mcg two or three times weekly in combination with insulin (42672,42783). Chromium picolinate has also been associated with weight gain in young females who do not exercise and in those following a weight-lifting program (1938).

Gastrointestinal ...Orally, chromium in the form of chromium picolinate, chromium polynicotinate, chromium-containing brewer's yeast, or chromium-containing milk powder may cause nausea, vomiting, diarrhea, decreased appetite, constipation, flatulence, or gastrointestinal upset (14325,42594,42607,42622,42643,42679).
Long-term exposure to heavy metals, including chromium, has been associated with increased risk of gallbladder disease and cancer (42682,42704).

Genitourinary ...Orally, chromium polynicotinate has been associated with disrupted menstrual cycles in patients taking the supplement to prevent weight gain during smoking cessation (42643).

Hematologic ...Anemia, hemolysis, and thrombocytopenia were reported in a 33 year-old female taking chromium picolinate 1200-2400 mcg daily for 4-5 months (554). The patient received supportive care, blood product transfusions, and hemodialysis and was stabilized and discharged a few days later. Lab values were normal at a one-year follow-up.

Hepatic ...Liver damage has been reported for a 33-year-old female taking chromium picolinate 1200 mcg daily for 4-5 months (554). Also, acute hepatitis has been reported in a patient taking chromium polynicotinate 200 mcg daily for 5 months (9141). Symptoms resolved when the product was discontinued. Two cases of hepatotoxicity have been reported in patients who took a specific combination product (Hydroxycut), which also contained chromium polynicotinate in addition to several herbs (13037).

Musculoskeletal ...Acute rhabdomyolysis has been reported for a previously healthy 24-year-old female who ingested chromium picolinate 1200 mcg over a 48-hour time period (42786). Also, chromium polynicotinate has been associated with leg pain and paresthesia in patients taking the supplement to prevent weight gain during smoking cessation (42643).

Neurologic/CNS ...Orally, chromium picolinate may cause headache, paresthesia, insomnia, dizziness, and vertigo (6860,10309,14325,42594). Vague cognitive symptoms, slowed thought processes, and difficulty driving occurred on three separate occasions in a healthy 35-year-old male after oral intake of chromium picolinate 200-400 mcg (42751). Transient increases in dreaming have been reported in three patients with dysthymia treated with chromium picolinate in combination with sertraline (2659). A specific combination product (Hydroxycut) containing chromium, caffeine, and ephedra has been associated with seizures (10307). But the most likely causative agent in this case is ephedra.

Psychiatric ...Orally, chromium picolinate has been associated with irritability and mood changes in patients taking the supplement to lose weight, while chromium polynicotinate has been associated with agitation and mood changes in patients taking the supplement to prevent weight gain during smoking cessation (6860,42643).

Renal ...Orally, chromium picolinate has been associated with at least one report of chronic interstitial nephritis and two reports of acute tubular necrosis (554,1951,14312). Laboratory evidence suggests that chromium does not cause kidney tissue damage even after long-term, high-dose exposure (7135); however, patient- or product-specific factors could potentially increase the risk of chromium-related kidney damage. More evidence is needed to determine what role, if any, chromium has in potentially causing kidney damage.
Intravenously, chromium is associated with decreased glomerular filtration rate (GFR) in children who receive long-term chromium-containing total parenteral nutrition - TPN (11787). Topically, burns caused by chromic acid, a hexavalent form of chromium, have been associated with acute chromium poisoning with acute renal failure (42699). Early excision of affected skin and dialysis are performed to prevent systemic toxicity.

Other ...Another form of chromium, called hexavalent chromium, is unsafe. This type of chromium is a by-product of some manufacturing processes. Chronic exposure can cause liver, kidney, or cardiac failure, pulmonary complications, anemia, and hemolysis (9141,11786,42572,42573,42699). Occupational inhalation of hexavalent chromium can cause ulceration of the nasal mucosa and perforation of the nasal septum, and has been associated with pneumoconiosis, allergic asthma, cough, shortness of breath, wheezing, and increased susceptibility to respiratory tract cancer and even stomach and germ cell cancers (42572,42573,42601,42610,42636,42667,42648,42601,42788,90056,90066). Although rare, cases of interstitial pneumonia associated with chromium inhalation have been reported. Symptoms resolved with corticosteroid treatment (42614).

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General ...Orally, gymnema seems to be well tolerated.

Hepatic ...A case of drug-induced hepatitis characterized by weakness, fatigue, jaundice, and elevated liver enzymes, has been reported for a patient who consumed gymnema tea three times daily for 10 days. The patient was administered prednisone 60 mg once daily and was eventually tapered off prednisone and discharged. Laboratory values normalized after 6 months (95005). A case of hepatitis-associated aplastic anemia characterized by jaundice, elevated liver function tests, and pancytopenia has been reported for a patient who consumed gymnema 2 grams twice daily for at least a month. Treatment with ursodeoxycholic acid for 8 weeks led to resolution of cholestatic hepatitis; however, the pancytopenia was not responsive to treatment with immunosuppressive drugs and the patient died 5 months after presentation (110021). The exact reason for these adverse effects is not clear; they may have been idiosyncratic.

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General ...Orally, Phaseolus vulgaris extract seems to be well tolerated.
Most Common Adverse Effects:
Orally: Constipation, diarrhea, flatulence, nausea, stomach pain, and vomiting.
Serious Adverse Effects (Rare):
Orally: Hypersensitivity reactions, including anaphylaxis, in sensitive individuals.

Dermatologic ...Topically, Phaseolus vulgaris may cause contact dermatitis in sensitive individuals. A case of occupational contact dermatitis characterized by pruritus, erythema, eczema, and dyspnea has been reported for a 41-year-old farmer who handled the green parts of Phaseolus vulgaris (29920).

Gastrointestinal ...Orally, an extract of the Phaseolus vulgaris variety white kidney bean, as well as alpha-amylase inhibitors isolated from Phaseolus vulgaris, might cause nausea, vomiting, diarrhea, flatulence, constipation, satiety, and stomach pains (11265,18223,29925,104874). Also, white kidney bean extract, taken orally along with carob gum, may cause constipation, flatulence, soft stools, and reduced levels of vitamin B12 and folic acid (10633). Consuming large amounts of raw or undercooked Phaseolus vulgaris beans or extract can cause nausea, vomiting, diarrhea, and gastroenteritis due to the content of phytohaemagglutinin, a plant protein lectin (18223,29916,93082). Cooking usually destroys lectins (18).

Immunologic ...Orally, Phaseolus vulgaris may cause hypersensitivity reactions, including anaphylaxis, in sensitive individuals. A case of severe anaphylactic shock requiring epinephrine and steroid treatment has been reported for a 23-year-old following ingestion of cooked kidney beans, a variety of Phaseolus vulgaris. The causative agents were reported to be phaseolin (vicilin) and phytohaemagglutinin (29918). Also, a case of angioedema resulting from type I hypersensitivity has been reported for a one-year-old child following inhalation of vapors from or ingestion of cooked white beans, another variety of Phaseolus vulgaris (29919).

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General ...Orally, vanadium is well tolerated when taken in amounts below the tolerable upper intake level (UL) of 1. 8 mg daily. Higher doses may cause adverse effects.
Most Common Adverse Effects:
Orally: Gastrointestinal adverse effects, including abdominal discomfort, diarrhea, flatulence, and nausea, when taken at doses above the UL.
Serious Adverse Effects (Rare):
Orally: Kidney damage, when taken long-term at high doses.
Topically: Contact dermatitis and other allergic reactions in sensitive individuals.

Cardiovascular ...Higher levels of vanadium in the body have been associated with a greater risk for hypertension (107923). However, it is unclear if oral supplementation with vanadium causes elevated blood pressure.

Dermatologic ...Allergic reactions to vanadium metal have been reported (99051,102095). A 68-year-old female developed an itchy, erythematous rash, ocular pruritus, and a positive skin test to vanadium after implantation of a vanadium-containing knee prosthesis (99051). Contact dermatitis, presenting as pruritic eczema of the hand, and a positive skin patch test to vanadium was reported in a 39-year-old male who worked with vanadium-containing tools (102095).

Endocrine ...In some cases, patients with diabetes have used very high doses (100 mg daily) safely for up to 4 weeks (3055,3056,3057). However, high body levels of vanadium have been associated with an increased incidence malnutrition-related diabetes mellitus (3020).

Gastrointestinal ...Orally, vanadium most commonly causes mild gastrointestinal upset (7135). There is concern that taking doses exceeding the tolerable upper intake level (UL) of 1.8 mg per day can increase the risk of gastrointestinal side effects and possibly lead to more severe toxicity. At higher doses, vanadium frequently causes gastrointestinal effects including abdominal discomfort, diarrhea, nausea, and flatulence (3012,3055,3056,3057,12557,12558). Doses of 22.5 mg daily can also cause cramps (3012). Vanadium has also been associated with green discoloration of the tongue, which is unrelated to dose (7135).

Immunologic ...Allergic reactions to vanadium metal have been reported (99051,102095). A 68-year-old female developed an itchy, erythematous rash, ocular pruritus, and a positive skin test to vanadium after implantation of a vanadium-containing knee prosthesis (99051). Contact dermatitis, presenting as pruritic eczema of the hand, and a positive skin patch test to vanadium was reported in a 39-year-old male who worked with vanadium-containing tools (102095).
Higher levels of vanadium in the body have been associated with a weakened immune system in children, as measured by reductions in CD3+ and CD4+ cell counts (107924). However, it is unclear if oral supplementation with vanadium causes a weakened immune system or increases the risk of infection.

Neurologic/CNS ...Orally, vanadium has been rarely associated with fatigue, lethargy, and focal neurological lesions, which are unrelated to dose (7135).

Pulmonary/Respiratory ...Severe and chronic respiratory tract disorders have been reported from occupational exposure to vanadium dusts (17).

Renal ...In some cases, patients with diabetes have used very high doses (100 mg daily) of vanadium safely for up to 4 weeks (3055,3056,3057). However, there is concern based on animal research that prolonged use of high doses might cause serious side effects including kidney damage (7135). High body levels of vanadium have also been associated with an increased incidence of kidney stones, distal renal tubular acidosis, hypokalemic periodic paralysis, and sudden unexplained nocturnal death (3020).

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