Chromium as an Essential Nutrient.
Chromium as an Essential Nutrient
prepared by Dr. Richard A. Anderson, Nutrient Requirements & Functions Lab., Beltsville Human Nutrition Research Center, U.S. Department of Agriculture
Introduction
Chromium (Cr) is an essential element required for normal carbohydrate and lipid metabolism. Chromium improves insulin function by increasing insulin binding to cells, insulin receptor number, and phosphorylation of the insulin receptor leading to increased insulin sensitivity. Normal dietary Cr intake for humans and farm animals is often suboptimal. Insufficient dietary intake of chromium leads to increases in risk factors associated with diabetes and cardiovascular diseases including elevated circulating insulin, glucose, triglycerides, total cholesterol, reduced HDL-cholesterol and impaired immune function. Within the past five years, improved chromium nutrition has been shown to improve glucose tolerance and type 1, type 2, gestational and steroid-induced diabetes. Chromium has also been shown to alleviate the diabetic symptoms and neuropathy of a patient on total parenteral nutrition.
Trivalent chromium is one of the least toxic nutrients and there have been no documented negative effects of supplemental chromium at intakes up to 1000 µg per day. While the toxic effects of chromium are limited to a small percentage of the population primarily exposed to chromium in occupational settings, the effects of marginal chromium nutrition appear widespread and may affect a large percentage of the general population.
Unless stated otherwise, “chromium” in this review refers to trivalent chromium. Hexavalent chromium can be reduced to trivalent, but there is no conversion of trivalent to hexavalent in living organisms.