Function:
Chromium is required for the maintenance of normal glucose metabolism, and it enhances the action of insulin.

Recommended Dietary Allowance:
35 mcg for men and 25 mcg for women.

Deficiency:
Deficiency is extremely rare occurring only in situations such as when all nutrition is being maintained by intravenous fluids with no chromium added.

Sources:
Meat, eggs, cheeses, whole grains, nuts and brewer's yeast are good sources of chromium.

Toxicity and UL:
Chromium present in foods or contained in currently available dietary supplements poses no risk therefore no UL has been set.

Recommendation:
As with other minerals a diet high in calories is needed to reach the AI for chromium on a daily basis, and supplementation in the range of 100 to 200 mcg per day may be beneficial. Doses of 600 to 1,000 mcg daily may improve the diabetic or pre-diabetic state.

For more information:
http://osu.orst.edu/dept/lpi/infocenter/vitamins/vitaminC/c.html