Chromium is a mineral that is primarily found in two forms: trivalent (chromium 3+) and

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1 Chelsea Rice KNH 413: Medical Nutrition Therapy II April 21, 2014 Nutrient: Chromium 1. What is the nutrient? Chromium is a mineral that is primarily found in two forms: trivalent (chromium 3+) and hexavalent (chromium 6+). Trivalent is biologically active and found in food, whereas hexavalent is a toxic form that results from industrial pollution. Individuals require trace amounts of chromium, yet its mechanism of action in the body and exact amount needed for optimal health are not well defined. It is known to enhance the action of insulin and storage of carbohydrate, fat, and protein in the body. It also appears to be directly involved in carbohydrate, fat, and protein metabolism, yet more research is needed. Challenges in research include defining the types of people who respond to chromium supplementation, evaluating the chromium content of foods, chromium bioavailability, defining if a chromium-deficiency state exists in humans due to inadequate dietary intakes, and developing valid measure of chromium status. 2. What is the RDA/DRI for the nutrient? In 1989, the National Academy of Sciences determined an estimated safe and adequate daily dietary intake range for chromium. 50 to 200 mcg, was the range for adults and adolescents. DRI s were established in the year 2001; the research was insufficient to determine RDAs, therefore AIs were developed based information found in studies with findings on average intakes of chromium from dietary intake. Below is a table with the Adequate Intakes (AIs) for chromium.

2 Age Infants and children Males Females Pregnancy Lactation 0 to 6 months to 12 months to 3 years 11 4 to 8 years 15 9 to 13 years to 18 years to 50 years >50 years mcg = micrograms 3. How is the nutrient metabolized? The route by which chromium enters the body is the digestive system. Chromium is present both in the inorganic form and as organic complexes found in food. Absorption of chromium is low in the intestine, ranging from 0.5 to 2.0%. The mechanism has not yet been fully understood. Once the chromium is absorbed, it circulates as free Cr 3+, as Cr 3+ bound to transferrin or other plasma proteins, or as complexes. This circulating chromium is then taken up by tissues and distributed in the body. It is excreted mainly through urine by glomerular filtration or bound to low molecular weight organic transporters.

3 4. What are food sources of the nutrient? Most foods in which chromium is found in only provide small amounts per serving. Good sources include meat and whole-grain products, fruits, vegetables, and spices. Foods high in simple sugars are low in chromium. The following table provides information about the approximate values of chromium in each food. Food Chromium (mcg) Broccoli, ½ cup 11 Grape juice, 1 cup 8 English muffin, whole wheat, 1 4 Potatoes, mashed, 1 cup 3 Garlic, dried, 1 teaspoon 3 Basil, dried, 1 tablespoon 2 Beef cubes, 3 ounces 2 Orange juice, 1 cup 2 Turkey breast, 3 ounces 2 Whole wheat bread, 2 slices 2 Red wine, 5 ounces 1 13 Apple, unpeeled, 1 medium 1 Banana, 1 medium 1

4 Food Chromium (mcg) Green beans, ½ cup 1 5. What disease states alter the nutrients metabolism? Chromium research is currently being conducted to conclude if this nutrient has a connection to various health conditions such as diabetes, blood lipid levels, weight loss, and body composition. Chromium deficiency impairs the body s ability to use glucose to meet its energy needs and raise the requirements of insulin; therefore it has been suggested that supplementing chromium might help to control this disease yet it is inconclusive and controversial. Chromium has also been found in some study to decrease cholesterol and triglyceride levels, yet supplements have shown no favorable effects on blood lipids in other studies. This nutrient is also claimed to reduce body fat and increase lean muscle mass. Many of the studies have failed to adequately control participates food intakes, as well as have only included a small number of subjects for a short duration. Therefore these conclusions are also controversial. 6. What are the tests or procedures to assess the nutrient level in the body? Chromium levels can be tested through blood or serum tests. Cr (VI) and complexes of Cr (III) can be determined in the plasma and erythrocytes. Cr (VI) enters red blood cells, but Cr(III) does not; therefore making it possible to distinguish sources and types of exposure. Levels can also be tested through urinary tests, but only reflects absorption over the past 1 or 2 days. 7. What is the drug nutrient interactions? The following medications may impair chromium absorption or enhance excretion: Antacids, corticosteroids, H2 blockers, and proton-pump inhibitors. These medications may increase

5 chromium absorption or may have their effects enhanced if taken with chromium: Beta-blockers, corticosteroids, insulin, nicotinic acid, NSAIDS, and prostaglandin inhibitors. 8. How is the nutrient measured? The nutrient is measured through blood, serum, or urinary tests. Since very little of this nutrient is absorbed, levels are usually very low. 9. What is the Upper Tolerable Limits? There are few serious adverse effects that have been linked to consuming too much chromium. Therefore an Upper Tolerable Limit has not been established. 10.What are the physical signs of deficiency? Evidence of actual chromium deficiency in humans is rare. In the 1960 s, three hospitalized patients were fed intravenously after showing signs of diabetes such as weight loss, neuropathy, and impaired glucose tolerance. When chromium was added to their feeding solution, the diabetes symptoms diminished. Even though this is the only sign of a chromium deficiency, this nutrient is commonly added to intravenous solutions. 11.What are physical signs of toxicity? The trivalent form of chromium is not considered a health hazard and has no signs of toxicity. On the other hand, the hexavalent form of chromium can be toxic. Acute poisoning is likely to occur through the oral route (usually accidental or intentional [suicide], not occupational or environmental), whereas chronic poisoning is usually from inhalation or skin contact. Physical signs include intense GI irritation, nausea, vomiting, diarrhea, vertigo, fever, muscle cramps, renal failure, intravascular hemolysis, circulatory collapse, liver damage, coma, and even death.

6 References Dietary Supplement Fact Sheet: Chromium Health Professional Fact Sheet. (n.d.). Retrieved from Nelms, M. N. (2011). Nutrition therapy and pathophysiology. Belmont, CA: Wadsworth, Cengage Learning.

Digestion and Excretion

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