Chromium (Cr) is an essential trace mineral nutrient required for normal sugar and fat metabolism. Chromium functions primarily by potentiating the action of insulin. Chromium occurs primarily in the trivalent and hexavalent forms; the form in higher organisms is trivalent. This mineral occurs throughout the body with highest concentrations in the liver, kidney, spleen and bone.
Works with insulin in the metabolism of sugar and stabilizes blood sugar levels; cleans the arteries by reducing Cholesterol & Triglyceride levels; helps transport amino acids to where the body needs them; helps control the appetite; medical research has shown that persons with low levels of Chromium in their bodies are more susceptible to having cancer and heart problems and becoming diabetic.
Signs of deficiency include impaired glucose tolerance and elevated circulating insulin. In some studies, chromium supplementation has reduced total serum cholesterol, triglycerides and apolipoprotein B and increased HDL-cholesterol. May result in glucose intolerance in diabetics; arteriosclerosis, heart disease, depressed growth, obesity, tiredness.
The Estimated Safe and Adequate Daily Dietary Intake (ESADDI) for adults is 50 to 200 µg. Usual dietary intakes in the U.S. are about 25 µg/day for women and 33 µg/day for men. Breast-fed infants consume less than 1 µg Cr/day and the ESADDI for infants is 10 to 40 µg/day. The current ESADDI for chromium needs to be reevaluated.
Meat, poultry, fish and dairy products are generally low in chromium. Fruits, vegetables whole grains and seeds are better sources but have variable concentrations. Processing foods with stainless steel equipment may increase their chromium concentration, especially if the foods are acidic. In addition, there are differences in bioavailability and biological activity of the different complexes found in foods.
Both solubility and oxidation state affect the potential for toxicity; furthermore, the type of complex may impact toxicity. Toxic effects are limited primarily to industrial exposure to hexavalent chromium, which is much more toxic than the trivalent form. The hexavalent chromium compounds may be carcinogenic. The acidity of the stomach promotes reduction of hexavalent chromium to the trivalent form. Most of the chromium absorbed from the gastrointestinal tract is trivalent. The Reference Dose (RfD) for trivalent chromium is 1 mg/kg/day. This level is more than 300-fold the upper limit of the ESADDI, making trivalent chromium one of the least toxic nutrients.