James Meschino DC, MS, ROHP
Chromium is an essential trace element required for maintenance of normal glucose metabolism. The function of chromium is directly related to the function of insulin, as chromium enhances (potentiates) the activity of insulin. Some human studies demonstrate that chromium supplementation results in improvement of glucose intolerance. Thus, it may have important applications for diabetics, hypoglycemic patients, and in Syndrome X (the metabolic syndrome).
Insulin-chromium interactions are not restricted to glucose metabolism. Animal and human studies indicate that chromium stimulates amino acid transport into the cells with a corresponding increase in protein synthesis.
Only the trivalent state of chromium is biologically active (nutritional chromium). By contrast the hexavalent form of chromium used as metal alloys by industry (industrial chromium) can be extremely toxic.
The chromium concentration of most body tissue decreases steadily as we age. As well, increasing impairment of glucose tolerance throughout normal pregnancy has been amply documented, and the changes in chromium concentration in the plasma may reflect decreased glucose tolerance or may actually reflect deficiency.
Concentration of chromium in the hair is ten times higher than in blood, and hair concentration has been suggested as a means of assessing chromium status.
Absorption and Metabolism
The exact mechanism of chromium absorption is not known, but it is not simple diffusion. Chromium is transported in the plasma in combination with transferrin. Unlike other metals, once chromium is absorbed, it is almost entirely excreted in the urine. Thus, daily intake is important to optimize chromium’s functions in the body. Generally speaking, absorption of inorganic chromium found in food and water appears to be only about one percent. Organically-bound chromium (e.g., GTF-chromium, chromium-chelates found in many supplements) permits a bioavailability of 10-25 percent.
The total amount of chromium found in the body averages less than 6 mgs. The hair, spleen, kidney and testes contain the highest concentrations.1,2
Recommended Daily Allowance (Chromium)
There is no official RDA for chromium, but the following recommendations have been suggested:
|Age Group||Dosage (mcg)|
|0 – 6 mths||10 – 40|
|6 – 12 mths||20 – 60|
|1 – 3 yrs||20 – 80|
|4 – 6 yrs||30 – 120|
|7 years and older||50 – 2003|
Supplementation Studies and Clinical Applications
- Glucose Intolerance
More than 15 controlled studies demonstrate that chromium supplementation has a positive effect on impaired glucose tolerance, by potentiating the action of insulin. This has important implications for hypoglycemics and Type II diabetics.4
In clinical studies in non-insulin dependent diabetes mellitus (NIDDM), supplementation with chromium has been shown to decrease fasting glucose levels, improve glucose tolerance, lower insulin levels, decrease total cholesterol and triglycerides, and increase HDL-cholesterol levels.5-8 In most of these studies, subjects ingested a minimum of 200 mcg of chromium from a supplement, daily.
- Cholesterol and Triglyceride Lowering
Chromium supplementation has been shown to lower cholesterol and triglycerides in both diabetic and non-diabetic subjects. Many forms of chromium have demonstrated this effect, but the value appears to be only in those with low initial chromium nutritional status. The typical changes are a 10 percent reduction in total cholesterol and triglycerides and a two percent increase in HDL.9-14
These are significant changes as every one percent decrease in total cholesterol corresponds to a 2-3 percent reduction in heart disease and stroke. Every one percent increase in HDL-cholesterol levels carries a 2-4 percent decrease in risk of cardiovascular disease.15
- Body Fat Reduction and Lean Mass Gains
Chromium supplementation has been shown to facilitate reductions in body fat and increase lean muscle mass. Lean mass gains have been especially noteworthy in subjects taking chromium supplements in conjunction with resistance training, in both young males and females.
However, even in older and elderly subjects chromium supplementation has produced significant reductions in body fat and moderate increases in muscle mass compared to placebo.
Typical doses for weight loss and lean mass gains have used 200-400 mcg per day. Additional studies are underway to determine the degree to which chromium may be helpful as a weight loss and anabolic aid.2,16,17,18 Presumably chromium is effective in these applications due to its ability to increase insulin sensitivity, thereby lowering plasma insulin levels. Higher insulin levels tend to convert more carbohydrates into fat and insulin resistance decreases protein synthesis in muscles and amino acid uptake.2
- Glucose Intolerance: 200-400 mcg per day
- Cholesterol and Triglyceride: 200-1,000 mcg per day
- Weight Loss and Lean Mass Gains: 200-400 mcg per day2
- Type-II Diabetics: 500 mcg of chromium, taken twice per day has been shown to decrease glycosylated hemoglobin, glucose, insulin and cholesterol variables19
NB: Chromium supplementation has been shown to reverse corticosteroid–induced Diabetes (200-1000 mcg).20
Side Effects and Toxicity
Trivalent chromium (nutritional chromium) has a very large safety range and there have been no documented signs of chromium toxicity in any of the nutritional studies at levels up to 1 mg (1,000 mcg) per day.21
Some patients have reported increased dream vividness and decreased sleep requirements with chromium supplementation taken at 7:30 p.m., daily (50 mcg).22
At levels of intake between 1,200 mcg and 3,400 mcg of chromium picolinate a case of anemia, liver dysfunction and other problems appeared after four to five months.23
Chromium supplementation may enhance the effects of drugs for diabetes (e.g., insulin, blood-sugar lowering agents) and possibly lead to hypoglycemia. Therefore, diabetics taking these medications should supplement chromium only under the supervision of their attending physician.
Doses of glyburide (a hypoglycemic sulfonylurea drug used to lower blood sugar in type II diabetics) will need to be lowered if chromium supplementation is initiated, in most cases.
Insulin-dependent diabetics may also be required to lower their insulin dosage if chromium supplementation is implemented.24
- Corticosteroid drugs – may increase urinary loss of chromium.21
- Insulin (Type-I Diabetics) – chromium can potentiate the action of insulin, thus affecting insulin dose requirements (do not supplement with chromium without cooperation of attending diabetic physician).25
- Refined Sugars: excess sugar intake has been shown to increase urinary loss of chromium.26
- High Carbohydrate Diet: high carbohydrate consumption has been shown to increase the urinary loss of chromium.27
Pregnancy and Lactation
During pregnancy and lactation, the only supplements that are considered safe include standard prenatal vitamin and mineral supplements. All other supplements or dose alterations may pose a threat to the developing fetus and there is generally insufficient evidence at this time to determine an absolute level of safety for most dietary supplements other than a prenatal supplement. Any supplementation practices beyond a prenatal supplement should involve the cooperation of the attending physician (e.g., magnesium and the treatment of preeclampsia.)
References: Pregnancy and Lactation
1. Encyclopedia of Nutritional Supplements. Murray M. Prima Publishing 1998.
2. Reavley NM. The New Encyclopedia of Vitamins, Minerals, Supplements, and Herbs. Evans and Company Inc. 1998.
3. The Healing Power of Herbs (2nd edition). Murray M. Prima Publishing 1995.
4. Boon H and Smith M. Health Care Professional Training Program in Complementary Medicine. Institute of Applied Complementary Medicine Inc. 1997.
- Standard Textbooks of Nutritional Science:
– Shils M, Shike M, Olson J, Ross C. Modern Nutrition in Health and Disease. 9th ed. Baltimore, MD: Lippincott Williams & Wilkins; 1993.
– Escott-Stump S, Mahan LK, editors. Food, Nutrition and Diet Therapy. 10th ed. Philadelphia, PA: W.B. Saunders Company; 2000.
– Bowman B, Russell RM, editors. Present Knowledge in Nutrition, 8th ed. Washington, DC:.ILSI Press; 2001.
– Kreutler PA, Czajka-Narins DM, editors. Nutrition in Perspective. 2nd ed. Upper Saddle River, NJ: Prentice Hall Inc.; 1987.
- Fisher J. The Chromium Program. New York, NY: Harper and Row; 1990.
- Murray M. Encyclopedia of Nutritional Supplements. Rocklin, CA: Prima Publishing; 1996. 194-8.
- Mertz W. Chromium in human nutrition: a review. J Nutr 1993;123:626-33.
- 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.
- Mossop RT. Effects of Chromium (III) on fasting blood glucose, cholesterol, and cholesterol HDL levels in diabetics. Centr Afr J Med 1983;29:80-2.
- Rabinowitz MB, Gonick HC, Levin SR, et al. Effect of Chromium and yeast supplements on carbohydrate metabolism in diabetic men. Diabetes Care 1983;6:319-27.
- Anderson RA. Chromium, glucose tolerance, and diabetes. Biological Trace Element Research 1992;32:19-24.
- Lee NA, Reasner CA. Beneficial effect of Chromium supplementation on serum triglyceride levels in NIDDM. Diabetes Care 1994;17:1449-52.
- Offenbach E, Pistunyer F. Beneficial effect of Chromium-rich yeast on glucose tolerance and blood lipids in elderly patients. Diabetes 1980;29:919-25.
- Press RI, Geller J, Evans GW. The effect of Chromium picolinate on serum cholesterol and apolipoprotein fractions in human subjects. Western J Med 1993;152:41-5.
- Wang MM, Fox EA, Stoecker BJ, Menendez CE, Chan SB. Serum cholesterol of adults supplemented with brewer’s yeast or Chromium Chloride. Nutr Res 1989;9:989-98.
- Roeback JR, Hla KM, Chambless LE, Fletcher RH. Effects of Chromium supplementation on serum high-density lipoprotein cholesterol levels in men taking beta-blockers. Annals Int Med 1991;115:917-24.
- Lefavi RG, Wilson GD, Keith RE, Anderson RA, Blessing DL, Hames CG, et al. Lipid-lowering effect of a dietary Chromium (III) Nicotinic Acid complex in male athletes. Nutr Res 1993;13:239-49.
- Lavie CJ, O’Keefe JH, Blonde L, et al. High-density lipoprotein cholesterol: recommendations for routine testing and treatment. Postgrad Med 1990;87(7):36-44,47,51
- McCarthy MG. Hypothesis: Sensitization of insulin-dependent hypothalamic glucoreceptors may account for the fat-reducing effects of Chromium Picolinate. J Optimal Nutr 1993;21:36-53.
- Evans GW, Pouchnik DJ. Composition and biological activity of chromium-pyridine carbosylate complexes. J Inorgranic Biochemistry 1993;49:177-87.
- Katts GR, Ficher JA, Blum K. The effects of Chromium Picolinate supplementation on body composition in different age groups. Age 1991;14(4):138 (Abstract #40).
- Anderson RA, Cheng N, Bryden NA, Polansky MM, Cheng N, Chi J et al. Elevated intakes of supplemental Chromium improves glucose and insulin variables in individuals with type 2 diabetes. Diabetes 1997; 11:1786-91.
- Revina A, et al. Reversal of corticosteroid-induced diabetes mellitus with supplemental Chromium. Diab Med 1999; 16(2):164-7.
- Anderson RA. Chromium, as an essential nutrient for humans. Regul Toxicol Pharmacol 1997;26(Suppl Pt 2): 35S-41S.
- Schrauzer GN, Shrestha KP, Flores MP. Somatopsychological effects of Chromium supplementation. J Nutr Med 1992;3:43-8.
- Cerulli J, Grabe DW, Gauthier I, Malone M, McGoldrick MD. Chromium Picolinate toxicity. Ann Pharmacother 1998;32:438-41.
- Healthnotes 1998-2002. Available from: URL: http://www.healthnotes.com.
- Studies presented at the Annual Scientific Sessions of the American Diabetes Association, San Francisco, CA, 1996.
- Kozlovsky AS, Moser PB, Reiser S, Anderson RA. Effects of diets high in simple sugars on urinary chromium losses. Metabolism 1986;35(6):515-8.
- Anderson RA, Bryden NA, Polansky MM. Urinary Chromium excretion and insulinogenic properties of carbohydrates. Am J Clin Nutr 1990;51(5):864-8.