Chromium

chromium.jpg (9428 bytes)

Structure:

Some solid chromium is shown above.  The trivalent form of chromium is the one which is important nutritionally. The hexavalent form is toxic, but is generally not found in food sources.

Function:

Chromium stimulates insulin sensitivity in the body, which can help Type II (non-insulin dependent) Diabetes patients control their sugar levels more effectively.   There is a possibility that taking 200-400 g of chromium a day can help weight loss in moderately obese people, although there is conflicting evidence to support this. The idea that chromium can help to increase muscle mass and overall strength has also been contested. Chromium is also involved in sugar and fat metabolism on which sufficient amounts have a positive effect. Chromium deficiency may result in increased circulating insulin levels and impaired glucose tolerance. The RDA is 50-200g for men and women. There is no specified UL as no adverse effects from taking large doses of chromium have been recorded. However occupational exposure to hexavalent chromium may be dangerous.

Mechanism:

Chromium is a component of Glucose Tolerance Factor, a naturally occurring complex between chromium, nicotinic acid, and the amino acids glycine, glutamate, cysteine, or glutathione. Glucose Tolerance Factor stimulates the effect of insulin, probably by facilitating its binding to cell receptor sites.

Sources:

Chromium is found in fruit and vegetables especially mushrooms, vegetable oils, whole grains, wheat germ, seeds, liver and brewer's yeast. Chromium is lost during food processing.

Facinating fact: Some concern has been voiced that most Americans may be marginally deficient in chromium.