Chromium: Benefits, Dosage, and Safety

What chromium is

Chromium, as trivalent (+3) chromium, is a trace element naturally present in many foods and available as a dietary supplement. It is distinct from hexavalent (+6) chromium, a toxic industrial by-product. Trivalent chromium is thought to potentiate insulin action, possibly by forming chromodulin, a low-molecular-weight chromium-binding substance that helps activate the insulin receptor. In 2001 the Food and Nutrition Board considered chromium an essential nutrient based on its effects on insulin action, but more recent research and a 2014 European Food Safety Authority opinion questioned whether it is truly essential, since no absence or deficiency state has been shown to produce abnormalities reversible by chromium. In blood, most chromium is bound to plasma proteins, particularly transferrin, and it accumulates mainly in the liver, spleen, soft tissue, and bone.

What it does

• May help potentiate the action of insulin, contributing to carbohydrate, lipid, and protein metabolism
• Proposed to form chromodulin, which may help activate the insulin receptor
• May have antioxidant effects

How much chromium per day

These are population reference values from the NIH and the Dietary Reference Intakes. They are targets for healthy people, not personal prescriptions. The last column is the Tolerable Upper Intake Level, the most you should get from all sources combined.

Deficiency and who is at risk

Chromium deficiency has not been reported in healthy populations, and no definitive deficiency symptoms have been established. Adverse metabolic and neurological effects reported in a few 1970s-1980s case studies of patients on long-term total parenteral nutrition (including hyperglycemia, glucose intolerance, unexplained weight loss, peripheral neuropathy, and confusion) were once attributed to chromium deficiency, but recent evaluations concluded those studies do not demonstrate that healthy people can develop chromium deficiency. No validated method for determining chromium status and no clinically defined chromium deficiency state exists.

Who may need more

• Most people in the United States appear to get chromium intakes similar to the Adequate Intake from a typical diet
• Chromium deficiency is not recognized in healthy populations, so a general need for supplementation is not established
• People considering chromium for blood sugar, weight, or PCOS should note that evidence is inconclusive and should consult a health care provider

Food sources

Chromium is present in meats, grain products, fruits, vegetables, nuts, spices, brewer's yeast, beer, and wine, but amounts vary widely with soil, water, and processing. Higher-content examples per serving (from ODS Table 2): grape juice 1 cup 7.5 mcg, ham 3 oz 3.6 mcg, whole-wheat English muffin 3.6 mcg, brewer's yeast 1 tablespoon 3.3 mcg, orange juice 1 cup 2.2 mcg, beef 3 oz 2.0 mcg. Most dairy products and high-sugar foods are low in chromium.

Forms and absorption

Supplement forms include chromium picolinate, chromium nicotinate, chromium polynicotinate, chromium chloride, and chromium histidinate. Absorption of the various forms is similar and low: about 1.2% from chromium picolinate versus about 0.4% from chromium chloride, comparable to the roughly 0.4% to 2.5% absorbed from food. Compounds contain differing percentages of elemental chromium (for example, elemental chromium is about 12.4% of the weight of chromium picolinate); the Supplement Facts label declares the amount of elemental chromium. Multivitamin/mineral supplements typically provide 35 to 120 mcg; chromium-only supplements commonly provide 200 to 500 mcg and some up to 1,000 mcg. Ascorbic acid and prostaglandin inhibitors such as aspirin increase absorption, while oxalate and antacids inhibit it.

Safety, excess and interactions

Too much

The Food and Nutrition Board concluded that no adverse effects have been convincingly linked to high intakes of chromium from food or supplements, so it did not establish a Tolerable Upper Intake Level. It noted caution may be warranted because data are limited. According to isolated case reports, chromium supplements might cause weight loss, anemia, thrombocytopenia, liver dysfunction, renal failure, rhabdomyolysis, dermatitis, and hypoglycemia. People with renal or liver disease might be more susceptible to adverse effects from high chromium intakes. (Note: hexavalent chromium is a separate, toxic industrial compound and is not the form in supplements or food.)

Interactions to know

• Insulin: chromium might increase insulin sensitivity, and taking it with insulin could increase the risk of hypoglycemia
• Metformin and other antidiabetes medications: chromium may have an additive glucose-lowering effect, potentially increasing the risk of hypoglycemia
• Levothyroxine: taking chromium picolinate at the same time as levothyroxine decreased levothyroxine absorption over 6 hours in a small study

How status is measured

Not routinely measured. No validated method for determining chromium status and no clinically defined chromium deficiency state exists. Urinary chromium reflects recent intake and absorption but not body stores; hair, sweat, serum, and toenail levels have been studied but are not validated status markers.

Regulated as a dietary supplement under DSHEA, not as a drug; supplements are not FDA-approved to treat, cure, or prevent disease. The FDA Daily Value (DV) for chromium is 35 mcg for adults and children age 4 and older. The FDA permits one qualified health claim for chromium picolinate: "One small study suggests that chromium picolinate may reduce the risk of insulin resistance, and therefore possibly may reduce the risk of type 2 diabetes. FDA concludes, however, that the existence of such a relationship between chromium picolinate and either insulin resistance or type 2 diabetes is highly uncertain."

What the evidence supports

We grade the strength of evidence behind each common reason people take chromium, mirroring how the NIH describes it.