Dietary Supplement Fact Sheet
Chromium: What is it?
Chromium is a mineral that humans require in trace amounts, although its mechanisms of action in the body and the amounts needed for optimal health are not well defined. It is found primarily in two forms: 1) trivalent (chromium 3+), which is biologically active and found in food, and 2) hexavalent (chromium 6+), a toxic form that results from industrial pollution. This fact sheet focuses exclusively on trivalent (3+) chromium.
Chromium is known to enhance the action of insulin [1-3 ], a hormone critical to the metabolism and storage of carbohydrate, fat, and protein in the body [4 ]. In 1957, a compound in brewers' yeast was found to prevent an age-related decline in the ability of rats to maintain normal levels of sugar (glucose) in their blood [3 ]. Chromium was identified as the active ingredient in this so-called "glucose tolerance factor" in 1959 [5 ].
Chromium also appears to be directly involved in carbohydrate, fat, and protein metabolism [1-2 ,6-11 ], but more research is needed to determine the full range of its roles in the
body. The challenges to meeting this goal include:
- Defining the types of individuals who respond to chromium supplementation;
- Evaluating the chromium content of foods and its bioavailability;
- Determining if a clinically relevant chromium-deficiency state exists in humans due to inadequate dietary intakes; and
- Developing valid and reliable measures of chromium status [9 ].
Table of Contents
What foods provide chromium?
Chromium is widely distributed in the food supply, but most foods provide only small amounts (less than 2 micrograms [mcg] per serving). Meat and whole-grain products, as well as some fruits, vegetables, and spices are relatively good sources [12 ]. In contrast, foods high in simple sugars (like sucrose and fructose) are low in chromium [13 ].
Dietary intakes of chromium cannot be reliably determined because the content of the mineral in foods is substantially affected by agricultural and manufacturing processes and perhaps by contamination with chromium when the foods are analyzed [10 ,12 ,14 ]. Therefore, Table 1, and food-composition databases generally, provide approximate values of chromium in foods that should only serve as a guide.