Deficiencies of chromium have been reported. Case studies describe insulin-resistant glucose intolerance, weight loss, and, more rarely, neurologic findings. The CDC notes that chromium deficiency may lead to cardiovascular disease, decreased lean body mass, reduced sperm count, fasting hyperglycemia, and impaired glucose tolerance. Cr6+ (hexavalent chromium) is a carcinogen. Industrial exposure to high levels is associated with lung cancer, dermatitis, and skin ulcers.
Various chromium supplements are marketed to people with type 2 diabetes. The most common is chromium picolinate. The FDA currently concludes that the existence of a relationship between chromium picolinate and either insulin resistance or type 2 diabetes is 'highly uncertain.' Likewise, the American Diabetes Association currently notes that because studies have not definitively shown that chromium supplementation benefits those with diabetes or obesity, they do not recommend chromium supplementation.
