Chromium potentiates the biological actions of insulin, a hormone that is critical for the normal regulation of carbohydrate, lipid and protein metabolism. Evidence of chromium's role was first suggested in 1957 when a "glucose tolerance factor" (GTF), found in brewer's yeast, prevented an age-related decline of glucose tolerance in rats. Chromium III was identified shortly after as the active ingredient of GTF.
Chromium was declared an essential nutrient in 1977 after significant elevations in blood sugar levels were first observed in a hospitalized patient receiving total parenteral nutrition devoid of chromium (Food & Nutrition Board, 2001; Jeejeebhoy et al, 1977). Blood sugar levels returned to normal after the addition of chromium to her diet.