Chromium is an essential mineral found in concentrations of 20 parts of chromium per 1 billion parts of blood. It has functions in both animal and human nutrition. Organic chromium is an active ingredient of a substance called GTF (glucose tolerance factor); niacin and amino acids complete the formula.
Chromium stimulates the activity of enzymes involved in the metabolism of glucose for energy and the synthesis of fatty acids and cholesterol. Chromium appears to increase the effectiveness of insulin and its ability to handle glucose, preventing hypoglycemia (too much insulin) or diabetes (too little insulin). In the blood it competes with iron in the transport of protein. Chromium may also be involved in the synthesis of protein through its binding action with RNA molecules.
Measuring chromium content of food can be misleading because of the different forms in which it occurs and their varying absorption rate by the body. Inorganic chromium is only 1 percent or less absorb-able. The chromium in eggs is in a form that can not be completely utilized. The chromium-containing foods most biologically available to the body are brewer's yeast (the best), liver, beef, whole-wheat bread, beets and beet sugar molasses, and mushrooms.
Chromium is difficult to absorb. Only about 3 percent of dietary chromium is retained in the body. The mineral is stored primarily in the spleen, kidneys, and testes; small amounts are also stored in the heart, pancreas, lungs, and brain. Chromium has been found in some enzymes and in RNA. Excretion occurs mainly through urination, with minor amounts lost in the feces. The amount of chromium stored in the body decreases with age.
There is no Recommended Dietary Allowance for chromium. The daily chromium intake of humans is estimated to range from 80 to 100 micrograms.
Deficiency Effects and Symptoms
Even a very slight chromium deficiency will have serious effects on the body. Tests indicate systematic deficiency of chromium to be common in the United States, although it rarely occurs in other countries. Americans tend to be deficient because their soil does not contain an adequate supply and thus chromium cannot be absorbed by the crops or reach the water supply. The refining of foods is another probable cause of chromium loss.
A chromium deficiency may be a factor that will upset the function of insulin and result in depressed growth rates and severe glucose intolerance in diabetics. It is also believed that the interaction of chromium and insulin is not limited to glucose metabolism but also applies to amino acid metabolism. Chromium may inhibit the formation of aortic plaques, and a deficiency may contribute to atherosclerosis.
Pregnant women are particularity susceptible to chromium deficiency because the fetus uses so much. Postoperative patients receiving glucose intravenously for nourishment need extra chromium. Studies have shown that blood chromium drops greatly when 60 grams of glucose are administered. If the patient also has a virus infection, the blood chromium drops even more.
Beneficial Effect on Ailments
Chromium helps to regulate sugar levels in the blood. Infants suffering from kwashiorkor have benefited from oral administration of chromium. Schizophrenics need extra niacin and have impaired glucose tolerance; therefore it is possible they may greatly benefit from chromium supplementation, creating the formation of more GTF.