Role of chromium in human metabolism, with special reference to type 2 diabetes.

Abstract

when severe diabetic symptoms of a female patient on prolonged total parenteral nutrition (deficient in chromium) were alleviated by supplemental chromium. Two other similar studies on chromium supplementation in malnourished children and elderly people established the role of chromium in carbohydrate metabolism. 9-12 It is recognised as a nutritionally essential element with daily adequate intake (AI) of 25 µg for women and 35 µg for men 13 and with serum levels in healthy humans from developed countries of 2.3 - 40.3 nmol/l. 14 The US Environmental Protection Agency (EPA) has replaced acceptable daily intake with calculated reference dose (RfD). The RfD is calculated from the ‘no observed adverse effect level’ from animal or human experiments and applying a “uncertainty and modifying factor” to it. 15 The reflects a staggering 350 times the ‘estimated safe and adequate dietary intake’ of 50-200 µg. The ratio of RfD to estimated safe intake is less than two for zinc, about two for manganese and about six for selenium. The ‘estimated safe and adequate dietary intake’ being 350 times less than the RfD reflects the lack of toxicity or adverse effects of chromium III, and probably dietary supplementation is greatly underdosed. 16