Chromium

Chromium is also known as glucose tolerance factor (GTF) because of its involvement in helping cells use glucose. Chromium deficiency is associated with poor blood glucose maintenance (either hypo- or hyperglycemia), an excessive production of insulin (hyperinsulinemia), excessive fatigue, and a craving for sweet foods. (Hypoglycemia is low blood sugar; hyperglycemia is high blood sugar). It is also associated with irritability (a common condition with poor blood glucose control), weight gain, adult-onset diabetes, and increased risk of cardiovascular disease. There is some evidence that frequent intense exercise, which is common for serious athletes, may increase the risk of chromium deficiency. High consumption of simple sugars (sweets) may also place people at risk for deficiency. Dietary sources of chromium include whole grain breads and cereals, and meats. Nutritional supplements, commonly in the form of chromium picolinate, are taken as a means of reducing weight or body fat, but studies on this supplement have produced mixed results. Initial studies of chromium picolinate supplementation suggest that this supplement is effective for increasing muscle mass and decreasing body fat in bodybuilders and football players. However, subsequent controlled studies have failed to reach the same conclusions. Other supplements for chromium include chromium polynicotinate, chromium chloride, and high-chromium yeast. The adult DRI for chromium is 25 micrograms per day for females and 35 micrograms per day for males. There is no established safe upper limit, although an excess intake may result in chronic renal failure.

Because chromium is not well absorbed, there is little evidence to suggest that an excessive intake of chromium will result in toxicity. However, the toxicity of chromium has not been directly tested, so athletes should be cautious about taking supplements. One study suggests that chromium picolinate has the potential to alter DNA and thus produce mutated, cancerous cells.¹¹⁶ Taken together, studies of this trace mineral suggest that to maintain optimal chromium nutriture, athletes should consume foods low in sugar and a diet that contains whole grains and some meat (if not a vegetarian).