What is chromium?

Chromium is a mineral our bodies use in small amounts for normal body functions, such as digesting food. Chromium exists in many natural foods including brewer's yeast, meats, potatoes (especially the skins), cheeses, molasses, spices, whole-grain breads and cereals, and fresh fruits and vegetables. Drinking hard tap water supplies chromium to the body, and cooking in stainless-steel cookware increases the chromium content in foods.

You can buy chromium supplements alone in tablets or capsules or as part of a multivitamin. But because the human body needs very little chromium, most people get enough in their regular diet and do not require dietary supplements. Those at risk for chromium deficiency include people with diabetes and the elderly.

Chromium helps to move blood sugar (glucose) from the bloodstream into the cells to be used as energy and to turn fats, carbohydrates, and proteins into energy.

• Chromium may help some people with type 2 diabetes. It may help them control their blood sugar and may play a role in the management of type 2 diabetes. But more studies are needed to know how well it really works.
• Chromium supplements are promoted as being helpful in building muscle and burning fat and in helping the body use carbohydrates. But this has not been proved.
• Chromium may affect the eyes. There is a link between low chromium levels and increased risk of glaucoma.
• Chromium slows the loss of calcium, so it may help prevent bone loss in women during menopause.

The chromium found in foods will not hurt you. But taking excessive chromium supplements can lead to stomach problems and low blood sugar (hypoglycemia). Too much chromium from supplements can also damage the liver, kidneys, and nerves, and it may cause irregular heart rhythm. But side effects from taking chromium supplements are rare.

Antacids (including calcium carbonate) interfere with the absorption of chromium.

Being exposed to high levels of chromium on the job (such as in metallurgy and electroplating) has been linked not only to kidney damage but also to lung and other cancers as well as skin conditions such as eczema and other inflammations of the skin.

The U.S. Food and Drug Administration (FDA) does not regulate dietary supplements in the same way it regulates medicines. A dietary supplement can be sold with limited or no research on how well it works or on its safety.

Always tell your doctor if you are using a dietary supplement or if you are thinking about combining a dietary supplement with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a dietary supplement. This is especially important for women who are pregnant or breastfeeding.

When using dietary supplements, keep in mind the following:

• Like conventional medicines, dietary supplements may cause side effects, trigger allergic reactions, or interact with prescription and nonprescription medicines or other supplements you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
• The way dietary supplements are manufactured may not be standardized. Because of this, how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form of supplement that you buy in health food or grocery stores may not be the same as the form used in research.
• Other than for vitamins and minerals, the long-term effects of most dietary supplements are not known.