Chromium, a trace mineral, potentiates the action of insulin. Nutritional sources that contain sufficient amounts include carrots, potatoes, broccoli, whole grains, and molasses. Picolinate, a by-product of tryptophan that is paired with chromium in supplements, is said to help the body absorb chromium more efficiently.
(See also Overview of Dietary Supplements.)
Chromium picolinate is said to promote weight loss, build muscle, reduce body fat, lower cholesterol and triglyceride levels, and enhance insulin function. Although chromium deficiency impairs insulin function, there is little evidence that supplementation helps patients with diabetes, nor is there evidence that it benefits body composition or lipid levels.
The role of supplemental chromium is controversial, and the clinical data conflict. A 2002 meta-analysis evaluated 20 randomized clinical trials and concluded that the data indicated no effect of chromium on glucose or insulin levels in nondiabetic patients; results were inconclusive in diabetic patients (1). A rigorous analysis of randomized controlled trials involving patients with type 2 diabetes evaluated clinically meaningful outcomes (such as a hemoglobin A1C < 7% or a 0.5% or greater decrease in hemoglobin A1C) and found that at best chromium supplementation provides a small benefit. Specifically, in only 3 of 14 trials did HbA1C decrease to < 7% and in 5 of 14 trials HbA1C decreased by 0.5% or greater (2). A 2019 meta analysis evaluating impact of chromium on anthropometric indices in overweight or obese subjects found a small but significant decrease in weight, body mass index, and body fat percentage. The authors stated the effect size was medium, and the clinical relevance for weight loss is uncertain (3). Notably, a Cochrane review of randomized controlled trials of chromium picolinate in overweight or obese adults found a small but significant decrease in weight; however, the researchers stated there was no overall evidence to support use (4).
Randomized, controlled, clinical trials are needed to determine whether chromium can influence diabetes, lipid metabolism, or weight loss. These studies should control or adjust for baseline chromium status and the form of chromium used and be done in well-defined at-risk populations in whom food intake is monitored.
Several studies have demonstrated that daily doses up to 1000 mcg of chromium are safe. Some forms of chromium may contribute to gastrointestinal irritation and ulcers. Isolated cases of impaired kidney and liver function have been reported; thus, people with pre-existing kidney or liver disorders should avoid supplementation. Chromium supplements interfere with iron absorption.
Althuis MD, Jordan NE, Ludington EA, et al: Glucose and insulin responses to dietary chromium supplements: a meta-analysis. Am J Clin Nutr 76(1):148-155, 2002.
Costello RB, Dwyer JT, Bailey RL: Chromium supplements for glycemic control in type 2 diabetes: limited evidence of effectiveness. Nutr Rev 74(7):455-68, 2016. doi: 10.1093/nutrit/nuw011.
Tsang C, Taghizadeh M, Aghabagheri E, et al: A meta-analysis of the effect of chromium supplementation on anthropometric indices of subjects with overweight or obesity. Clin Obes 9(4):e12313, 2019. doi: 10.1111/cob.12313.
Tian H, Guo X, Wang X, et al: Chromium picolinate supplementation for overweight or obese adults. Cochrane Database Syst Rev (11):CD010063, 2013. doi: 10.1002/14651858.CD010063.pub2.
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
National Institutes of Health (NIH), National Center for Complementary and Integrative Health: General information on the lack of scientific evidence showing that any dietary supplement can help manage or prevent type 2 diabetes