Chromium: What is it?
Chromium is a mineral that humans require in trace amounts, although its mechanisms of action in the body and the amounts needed for optimal health are not well defined. It is found primarily in two forms: 1) trivalent (chromium 3+), which is biologically active and found in food, and 2) hexavalent (chromium 6+), a toxic form that results from industrial pollution. This fact sheet focuses exclusively on trivalent (3+) chromium.
Chromium is known to enhance the action of insulin [1-3], a hormone critical to the metabolism and storage of carbohydrate, fat, and protein in the body . In 1957, a compound in brewers’ yeast was found to prevent an age-related decline in the ability of rats to maintain normal levels of sugar (glucose) in their blood . Chromium was identified as the active ingredient in this so-called “glucose tolerance factor” in 1959 .
Chromium also appears to be directly involved in carbohydrate, fat, and protein metabolism [1-2,6-11], but more research is needed to determine the full range of its roles in the body. The challenges to meeting this goal include:
- Defining the types of individuals who respond to chromium supplementation;
- Evaluating the chromium content of foods and its bioavailability;
- Determining if a clinically relevant chromium-deficiency state exists in humans due to inadequate dietary intakes; and
- Developing valid and reliable measures of chromium status .
Table of Contents
- Chromium: What is it?
- What foods provide chromium?
- What are recommended intakes of chromium?
- What affects chromium levels in the body?
- When can a chromium deficiency occur?
- Who may need extra chromium?
- What are some current issues and controversies about chromium?
- What are the health risks of too much chromium?
- Chromium and medication interactions
- Supplemental sources of chromium
- Chromium and Healthful Diets
What foods provide chromium?
Chromium is widely distributed in the food supply, but most foods provide only small amounts (less than 2 micrograms [mcg] per serving). Meat and whole-grain products, as well as some fruits, vegetables, and spices are relatively good sources . In contrast, foods high in simple sugars (like sucrose and fructose) are low in chromium .
Dietary intakes of chromium cannot be reliably determined because the content of the mineral in foods is substantially affected by agricultural and manufacturing processes and perhaps by contamination with chromium when the foods are analyzed [10,12,14]. Therefore, Table 1, and food-composition databases generally, provide approximate values of chromium in foods that should only serve as a guide.
|Table 1: Selected food sources of chromium [12,15-16]|
|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|
|Green beans, ½ cup||1|
What are recommended intakes of chromium?
Recommended chromium intakes are provided in the Dietary Reference Intakes (DRIs) developed by the Institute of Medicine of the National Academy of Sciences . Dietary Reference Intakes is the general term for a set of reference values to plan and assess the nutrient intakes of healthy people. These values include the Recommended Dietary Allowance (RDA) and the Adequate Intake (AI). The RDA is the average daily intake that meets a nutrient requirement of nearly all (97 to 98%) healthy individuals . An AI is established when there is insufficient research to establish an RDA; it is generally set at a level that healthy people typically consume.
In 1989, the National Academy of Sciences established an “estimated safe and adequate daily dietary intake” range for chromium. For adults and adolescents that range was 50 to 200 mcg . In 2001, DRIs for chromium were established. The research base was insufficient to establish RDAs, so AIs were developed based on average intakes of chromium from food as found in several studies . Chromium AIs are provided in Table 2.
|Table 2: Adequate Intakes (AIs) for chromium |
|Age||Infants and children
|0 to 6 months||0.2|
|7 to 12 months||5.5|
|1 to 3 years||11|
|4 to 8 years||15|
|9 to 13 years||25||21|
|14 to 18 years||35||24||29||44|
|19 to 50 years||35||25||30||45|
mcg = micrograms
Adult women in the United States consume about 23 to 29 mcg of chromium per day from food, which meets their AIs unless they’re pregnant or lactating. In contrast, adult men average 39 to 54 mcg per day, which exceeds their AIs .
The average amount of chromium in the breast milk of healthy, well-nourished mothers is 0.24 mcg per quart, so infants exclusively fed breast milk obtain about 0.2 mcg (based on an estimated consumption of 0.82 quarts per day) . Infant formula provides about 0.5 mcg of chromium per quart . No studies have compared how well infants absorb and utilize chromium from human milk and formula [10,14].
What affects chromium levels in the body?
Absorption of chromium from the intestinal tract is low, ranging from less than 0.4% to 2.5% of the amount consumed [19-25], and the remainder is excreted in the feces [1,23]. Enhancing the mineral’s absorption are vitamin C (found in fruits and vegetables and their juices) and the B vitamin niacin (found in meats, poultry, fish, and grain products) . Absorbed chromium is stored in the liver, spleen, soft tissue, and bone .
The body’s chromium content may be reduced under several conditions. Diets high in simple sugars (comprising more than 35% of calories) can increase chromium excretion in the urine . Infection, acute exercise, pregnancy and lactation, and stressful states (such as physical trauma) increase chromium losses and can lead to deficiency, especially if chromium intakes are already low [28-29].
When can a chromium deficiency occur?
In the 1960s, chromium was found to correct glucose intolerance and insulin resistance in deficient animals, two indicators that the body is failing to properly control blood-sugar levels and which are precursors of type 2 diabetes . However, reports of actual chromium deficiency in humans are rare. Three hospitalized patients who were fed intravenously showed signs of diabetes (including weight loss, neuropathy, and impaired glucose tolerance) until chromium was added to their feeding solution. The chromium, added at doses of 150 to 250 mcg/day for up to two weeks, corrected their diabetes symptoms [7,30-31]. Chromium is now routinely added to intravenous solutions.
Who may need extra chromium?
There are reports of significant age-related decreases in the chromium concentrations of hair, sweat and blood , which might suggest that older people are more vulnerable to chromium depletion than younger adults . One cannot be sure, however, as chromium status is difficult to determine . That’s because blood, urine, and hair levels do not necessarily reflect body stores [9,14]. Furthermore, no chromium-specific enzyme or other biochemical marker has been found to reliably assess a person’s chromium status [9,34].
There is considerable interest in the possibility that supplemental chromium may help to treat impaired glucose tolerance and type 2 diabetes, but the research to date is inconclusive. No large, randomized, controlled clinical trials testing this hypothesis have been reported in the United States . Nevertheless, this is an active area of research.
What are some current issues and controversies about chromium?
Chromium has long been of interest for its possible connection to various health conditions. Among the most active areas of chromium research are its use in supplement form to treat diabetes, lower blood lipid levels, promote weight loss, and improve body composition.
Type 2 diabetes and glucose intolerance
In type 2 diabetes, the pancreas is usually producing enough insulin but, for unknown reasons, the body cannot use the insulin effectively. The disease typically occurs, in part, because the cells comprising muscle and other tissues become resistant to insulin’s action, especially among the obese. Insulin permits the entry of glucose into most cells, where this sugar is used for energy, stored in the liver and muscles (as glycogen), and converted to fat when present in excess. Insulin resistance leads to higher than normal levels of glucose in the blood (hyperglycemia).
Chromium deficiency impairs the body’s ability to use glucose to meet its energy needs and raises insulin requirements. It has therefore been suggested that chromium supplements might help to control type 2 diabetes or the glucose and insulin responses in persons at high risk of developing the disease. A review of randomized controlled clinical trials evaluated this hypothesis . This meta-analysis assessed the effects of chromium supplements on three markers of diabetes in the blood: glucose, insulin, and glycated hemoglobin (which provides a measure of long-term glucose levels; also known as hemoglobin A1C). It summarized data from 15 trials on 618 participants, of which 425 were in good health or had impaired glucose tolerance and 193 had type 2 diabetes. Chromium supplementation had no effect on glucose or insulin concentrations in subjects without diabetes nor did it reduce these levels in subjects with diabetes, except in one study. However, that study, conducted in China (in which 155 subjects with diabetes were given either 200 or 1,000 mcg/day of chromium or a placebo) might simply show the benefits of supplementation in a chromium-deficient population.
Overall, the value of chromium supplements for diabetes is inconclusive and controversial . Randomized controlled clinical trials in well-defined, at-risk populations where dietary intakes are known are necessary to determine the effects of chromium on markers of diabetes . The American Diabetes Association states that there is insufficient evidence to support the routine use of chromium to improve glycemic control in people with diabetes . It further notes that there is no clear scientific evidence that vitamin and mineral supplementation benefits people with diabetes who do not have underlying nutritional deficiencies.
The effects of chromium supplementation on blood lipid levels in humans are also inconclusive [1,8,38]. In some studies, 150 to 1,000 mcg/day has decreased total and low-density-lipoprotein (LDL or “bad”) cholesterol and triglyceride levels and increased concentrations of apolipoprotein A (a component of high-density-lipoprotein cholesterol known as HDL or “good” cholesterol) in subjects with atherosclerosis or elevated cholesterol or among those taking a beta-blocker drug [39-41]. These findings are consistent with the results of earlier studies [42-45].
However, chromium supplements have shown no favorable effects on blood lipids in other studies [46-51]. The mixed research findings may be due to difficulties in determining the chromium status of subjects at the start of the trials and the researchers’ failure to control for dietary factors that influence blood lipid levels [9-10].
Body weight and composition
Chromium supplements are sometimes claimed to reduce body fat and increase lean (muscle) mass. Yet a recent review of 24 studies that examined the effects of 200 to 1,000 mcg/day of chromium (in the form of chromium picolinate) on body mass or composition found no significant benefits . Another recent review of randomized, controlled clinical trials did find supplements of chromium picolinate to help with weight loss when compared wtth placebos, but the differences were small and of debatable clinical relevance . In several studies, chromium’s effects on body weight and composition may be called into question because the researchers failed to adequately control for the participants’ food intakes. Furthermore, most studies included only a small number of subjects and were of short duration .
What are the health risks of too much chromium?
Few serious adverse effects have been linked to high intakes of chromium, so the Institute of Medicine has not established a Tolerable Upper Intake Level (UL) for this mineral [10,14]. A UL is the maximum daily intake of a nutrient that is unlikely to cause adverse health effects. It is one of the values (together with the RDA and AI) that comprise the Dietary Reference Intakes (DRIs) for each nutrient.
Chromium and medication interactions
Certain medications may interact with chromium, especially when taken on a regular basis (see Table 3). Before taking dietary supplements, check with your doctor or other qualified healthcare provider, especially if you take prescription or over-the-counter medications.
|Table 3: Interactions between chromium and medications [14,53-55]|
|Medications||Nature of interaction|
||These medications alter stomach acidity and may impair chromium absorption or enhance excretion|
||These medications may have their effects enhanced if taken together with chromium or they may increase chromium absorption|
Supplemental sources of chromium
Chromium is a widely used supplement. Estimated sales to consumers were $85 million in 2002, representing 5.6% of the total mineral-supplement market . Chromium is sold as a single-ingredient supplement as well as in combination formulas, particularly those marketed for weight loss and performance enhancement. Supplement doses typically range from 50 to 200 mcg.
The safety and efficacy of chromium supplements need more investigation. Please consult with a doctor or other trained healthcare professional before taking any dietary supplements.
Chromium supplements are available as chromium chloride, chromium nicotinate, chromium picolinate, high-chromium yeast, and chromium citrate. Chromium chloride in particular appears to have poor bioavailability . However, given the limited data on chromium absorption in humans, it is not clear which forms are best to take.
Chromium and Healthful Diets
The federal government’s 2015-2020 Dietary Guidelines for Americans notes that “Nutritional needs should be met primarily from foods. … Foods in nutrient-dense forms contain essential vitamins and minerals and also dietary fiber and other naturally occurring substances that may have positive health effects. In some cases, fortified foods and dietary supplements may be useful in providing one or more nutrients that otherwise may be consumed in less-than-recommended amounts.”
For more information about building a healthy diet, refer to the Dietary Guidelines for Americans and the U.S. Department of Agriculture’s MyPlate.
The Dietary Guidelines for Americans describes a healthy eating pattern as one that:
- Includes a variety of vegetables, fruits, whole grains, fat-free or low-fat milk and milk products, and oils.
Whole grain products and certain fruits and vegetables like broccoli, potatoes, grape juice, and oranges are sources of chromium. Ready-to-eat bran cereals can also be a relatively good source of chromium.
- Includes a variety of protein foods, including seafood, lean meats and poultry, eggs, legumes (beans and peas), nuts, seeds, and soy products.
Lean beef, oysters, eggs, and turkey are sources of chromium.
- Limits saturated and trans fats, added sugars, and sodium.
- Stays within your daily calorie needs.
- Mertz W. Chromium occurrence and function in biological systems. Physiol Rev 1969;49:163-239.
- Mertz W. Chromium in human nutrition: a review. J Nutr 1993;123:626-33.
- Mertz W. Interaction of chromium with insulin: a progress report. Nutr Rev 1998;56:174-7.
- Porte Jr. D, Sherwin RS, Baron A (editors). Ellengerg & Rifkin’s Diabetes Mellitus, 6th Edition. McGraw-Hill, New York, 2003.
- Schwarz K, Mertz W. Chromium(III) and the glucose tolerance factor. Arch Biochem Biophys 1959;85:292-5.
- Hopkins Jr. LL, Ransome-Kuti O, Majaj AS. Improvement of impaired carbohydrate metabolism by chromium(III) in malnourished infants. Am J Clin Nutr 1968;21:203-11.
- Jeejeebhoy KN, Chu RC, Marliss EB, Greenberg GR, Bruce-Robertson A. Chromium deficiency, glucose intolerance, and neuropathy reversed by chromium supplementation in a patient receiving long-term total parenteral nutrition. Am J Clin Nutr 1977;30:531-8.
- Anderson R. Chromium. In: Trace Elements in Human and Animal Nutrition (edited by Mertz M). Academic Press, San Diego, CA, 1987, pp. 225-244.
- Lukaski HC. Chromium as a supplement. Annu Rev Nutr 1999;19:279-302.
- Stoecker BJ. Chromium. In: Present Knowledge in Nutrition, 8th Edition (edited by Bowman B, Russell R). ILSI Press, Washington, DC, 2001, pp. 366-372.
- Vincent JB. The potential value and toxicity of chromium picolinate as a nutritional supplement, weight loss agent and muscle development agent. Sports Med 2003;33:213-30.
- Anderson RA, Bryden NA, Polansky MM. Dietary chromium intake: freely chosen diets, institutional diets and individual foods. Biol Trace Elem Res 1992;32:117-21.
- Kozlovsky AS, Moser PB, Reiser S, Anderson RA. Effects of diets high in simple sugars on urinary chromium losses. Metabolism 1986;35:515-8.
- Institute of Medicine, Food and Nutrition Board. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. National Academy Press, Washington, DC, 2001.
- Cabrera-Vique C, Teissedre P-L, Cabanis M-T, Cabinis J-C. Determination and levels of chromium in French wine and grapes by graphite furnace atomic absorption spectrometry. J Agric Food Chem 1997;45:1808-11.
- Dattilo AM, Miguel SG. Chromium in health and disease. Nutr Today 2003;38:121-33.
- National Research Council, Food and Nutrition Board. Recommended Dietary Allowances, 10th Edition. National Academy Press, Washington, DC, 1989.
- Cocho JA, Cervilla JR, Rey-Goldar ML, Fdez-Lorenzo JR, Fraga JM. Chromium content in human milk, cow’s milk, and infant formulas. Biol Trace Elem Res 1992;32:105-7.
- Doisy RJ, Streeten DHP, Souma ML, Kalafer ME, Rekant SL, Dalakos TG. Metabolism of 51chromium in human subjects. In: Newer Trace Elements in Nutrition (edited by Mertz W, Cornatzer WE). Dekker, New York, 1971, pp. 155-68.
- Anderson RA, Polansky MM, Bryden NA, Patterson KY, Veillon C, Glinsmann WH. Effects of chromium supplementation on urinary Cr excretion of human subjects and correlation of Cr excretion with selected clinical parameters. J Nutr 1983;113:276-81.
- Bunker VW, Lawson MS, Delves HT, Clayton BE. The uptake and excretion of chromium by the elderly. Am J Clin Nutr 1984;39:797-802.
- Anderson RA, Kolovsky AS. Chromium intake, absorption and excretion of subjects consuming self-selected diets. Am J Clin Nutr 1985;41:1177-83.
- Offenbacher EG, Spencer H, Dowling HJ, Pi-Sunyer FX. Metabolic chromium balances in men. Am J Clin Nutr 1986;44:77-82.
- Anderson RA, Polansky MM, Bryden NA, Canary JJ. Supplemental-chromium effects on glucose, insulin, glucagon, and urinary chromium losses in subjects consuming controlled low-chromium diets. Am J Clin Nutr 1991;54:909-16.
- Anderson RA, Bryden NA, Patterson KY, Veillon C, Andon MB, Moser-Veillon PB. Breast milk chromium and its association with chromium intake, chromium excretion, and serum chromium. Am J Clin Nutr 1993;57:419-23.
- Offenbacher E. Promotion of chromium absorption by ascorbic acid. Trace Elem Elect 1994;11:178-81.
- Lim TH, Sargent T 3rd, Kusubov N. Kinetics of trace element chromium(III) in the human body. Am J Physiol 1983;244:R445-54.
- Anderson R. Stress Effects on Chromium Nutrition in Humans and Animals, 10th Edition. Nottingham University Press, England, 1994.
- Lukaski HC, Bolonchuk WW, Siders WA, Milne DB. Chromium supplementation and resistance training: effects on body composition, strength and trace element status of men. Am J Clin Nutr 1996;63:954-65.
- Freund H, Atamian S, Fischer JE. Chromium deficiency during total parenteral nutrition. JAMA 1979;241:496-8.
- Brown RO, Forloines-Lynn S, Cross RE, Heizer WD. Chromium deficiency after long-term total parenteral nutrition. Dig Dis Sci 1986;31:661-4.
- Davies S, Howard JM, Hunnisett A, Howard M. Age-related decreases in chromium levels in 51,665 hair, sweat, and serum samples from 40,872 patients — implications for the prevention of cardiovascular disease and type II diabetes mellitus. Metabolism 1997;46:469-73.
- Gibson RS. Principles of Nutritional Assessment, 2nd Edition. Oxford University Press, New York, 2005.
- Stoecker BJ. Chromium. In: Modern Nutrition in Health and Disease, 9th Edition (edited by Shils ME, Olson JA, Shike M, Ross AC.) Lippincott Williams and Wilkins, New York, 1999, pp. 277-282.
- Althuis MD, Jordan NE, Ludington EA, Wittes JT. Glucose and insulin responses to dietary chromium supplements: a meta-analysis. Am J Clin Nutr 2002;76:148-55.
- Cefalu WT, Hu FB. Role of chromium in human health and in diabetes. Diabetes Care 2004;27:2741-51.
- Evert AB, Boucher JL, Cypress M, Dunbar SA, Franz MJ, Mayer-Davis EJ, Neumiller JJ, Nwankwo R, Verdi CL, Urbanski P, Yancy WS Jr. Nutrition therapy recommendations for the management of adults with diabetes. Diabetes Care 2013;36:3821-42. [GLB Med abstract]
- Offenbacher E, Pi-Sunyer F. Chromium. In: Handbook of Nutritionally Essential Mineral Elements (edited by O’Dell B, Sunde R). Marcel Dekker, New York, 1997, pp. 389-411.
- Roeback Jr. JR, Hla KM, Chambless LE, Fletcher RH. Effects of chromium supplementation on serum high-density lipoprotein cholesterol levels in men taking beta-blockers. A randomized, controlled trial. Ann Intern Med 1991;115:917-24.
- Abraham AS, Brooks BA, Eylath U. The effects of chromium supplementation on serum glucose and lipids in patients with and without non-insulin-dependent diabetes. Metabolism 1992;41:768-71.
- Hermann J, Arquitt A. Effect of chromium supplementation on plasma lipids, apolipoproteins, and glucose in elderly subjects. Nutr Res 1994;14: 671-4.
- Doisy RJ, Streeten DHP, Freiberg JM, Schneider AJ. Chromium metabolism in man and biochemical effects. In: Trace Elements in Human Health and Disease, Volume 2: Essential and Toxic Elements (edited by Prasad A, Oberleas D). Academic Press, New York, 1976, pp. 79-104.
- Lifschitz ML, Wallach S, Peabody RA, Verch RL, Agrawal R. Radiochromium distribution in thyroid and parathyroid deficiency. Am J Clin Nutr 1980:33:57-62.
- Riales R, Albrink MJ. Effect of chromium chloride supplementation on glucose tolerance and serum lipids including high-density lipoprotein of adult men. Am J Clin Nutr 1981;34:2670-8.
- Mossop RT. Effects of chromium III on fasting blood glucose, cholesterol and cholesterol HDL levels in diabetics. Cent Afr J Med 1983;29:80-2.
- Anderson RA, Polansky MM, Bryden NA, Roginski EE, Mertz W, Glinsmann W. Chromium supplementation of human subjects: effects on glucose, insulin, and lipid variables. Metabolism 1983;32:894-9.
- Rabinowitz MB, Gonick HC, Levin SR, Davidson MB. Effects of chromium and yeast supplements on carbohydrate and lipid metabolism in diabetic men. Diabetes Care 1983;6:319-27.
- Uusitupa MI, Kumpulainen JT, Voutilainen E, Hersio K, Sarlund H, Pyorala KP, Koivistoinen PE, Lehto JT. Effect of inorganic chromium supplementation on glucose tolerance, insulin response, and serum lipids in noninsulin-dependent diabetics. Am J Clin Nutr 1983;38:404-10.
- Offenbacher EG, Rinko CJ, Pi-Sunyer FX. The effects of inorganic chromium and brewer’s yeast on glucose tolerance, plasma lipids, and plasma chromium in elderly subjects. Am J Clin Nutr 1985;42:454-61.
- Potter JF, Levin P, Anderson RA, Freiberg JM, Andres R, Elahi D. Glucose metabolism in glucose-intolerant older people during chromium supplementation. Metabolism 1985;34:199-204.
- Uusitupa MI, Mykkanen L, Siitonen O, Laakso M, Sarlund H, Kolehmainen P, Rasanen T, Kumpulainen J, Pyorala K. Chromium supplementation in impaired glucose tolerance of elderly: effects on blood glucose, plasma insulin, C-peptide and lipid levels. Br J Nutr 1992;68:209-16.
- Pittler MH, Stevinson C, Ernst E. Chromium picolinate for reducing body weight: meta-analysis of randomized trials. Int J Obes Relat Metab Disord 2003;27:522-9.
- Davis ML, Seaborn CD, Stoecker BJ. Effects of over-the-counter drugs on 51chromium retention and urinary excretion in rats. Nutr Res 1995;15:201-10.
- Kamath SM, Stoecker BJ, Davis-Whitenack ML, Smith MM, Adeleye BO, Sangiah S. Absorption, retention and urinary excretion of chromium-51 in rats pretreated with indomethacin and dosed with dimethylprostaglandin E2, misoprostol or prostacyclin. J Nutr 1997;127:478-82.
- Chromium. In: Natural Medicines Comprehensive Database, 2005. http://www.naturalmedicines.com.
- Nutrition Business Journal. NBJ’s Supplement Business Report 2003. Penton Media Inc., San Diego, CA, 2003.