Chromium is generally accepted as an essential trace mineral that potentiates insulin action and thus influences carbohydrate, protein, and fat metabolism. The biologically active form of chromium, sometimes called glucose tolerance factor (GTF), occurs naturally in brewers yeast. GTF has been proposed to be a complex of chromium, nicotinic acid (vitamin B3), and possibly the amino acids glycine, cysteine, and glutamic acid.
Many attempts have been made to isolate or synthesize natural GTF, but none have been entirely successful. The most promising approach to natural GTF is chromium polynicotinate, the active form of chromium in ChromeMate. No other synthetic chromium complex comes as close to natural GTF as chromium polynicotinate (niacin-bound chromium) in terms of biological activity and chemical structure. Chromium absorption is typically less than 2% efficient and variable depending on its chemical form. Studies have demonstrated that chromium from ChromeMate has a higher bioavailability than other chromium compounds, such as chromium picolinate or chloride. Tissues retained anywhere from 2 to 8 times more chromium from ChromeMate compared to chromium picolinate or chromium chloride. The typical dietary chromium intake in the U.S. can vary considerably depending on eating habits. Meats and unrefined whole grain cereal products, especially bran, are good sources of chromium. However, most self-selected diets contain less than 50 mcg per day, which is below the minimum of the Estimated Safe and Adequate Daily Dietary Intake established by the National Research Council, Food and Nutrition Board. Chromium requirements may be increased with high intake of refined carbohydrates and simple sugars, strenuous physical exercise or work, infection, or physical trauma.
References Olin KL et al. Comparative retention/absorption of 51chromium (51Cr) from 51Cr chloride, 51Cr nicotinate and 51Cr picolinate in a rat model. Trace Elem Electrolytes 1994;11:182-186. Lefavi R et al. Lipid-lowering effect of a dietary nicotinic acid-chromium (III) complex in male athletes. FASEB J 1991;5:A1645 (abstract). Mertz W. Chromium in human nutrition: a review. J Nutr 1993;123:626-633. Mertz W. Effects and metabolism of glucose tolerance factor. In: Present Knowledge in Nutrition, The Nutrition Foundation, Washington, D.C., 1976. Ch. 36, pp. 365-372. Morris BW et al. The trace element chromium--a role in glucose homeostasis. Am J Clin Nutr 1992;55:989-991. Urberg M et al. Hypocholesterolemic effects of nicotinic acid and chromium supplementation. J Fam Prac 1988;27:603-606. Wallach S. Clinical and biochemical aspects of chromium deficiency. J Am Coll Nutr 1985;4:107-120.