Harvard Health Letter

Is Vitamin E bad for your bones?

Normal doses are okay; megadoses can be dangerous.

Vitamin E is a popular supplement, hyped to improve your health for everything from the brain to the bedroom. However, the science backing up those claims is largely inconclusive. Now, a recent study published in the journal Nature Medicine further suggests that too much vitamin E may even weaken your bones.

Cartiginous Joint

Cartiginous joint

A. Vertebrae. B. Cartilage disk

Researchers found that rats given megadoses of vitamin E developed bones 20% weaker than those of rats on a normal diet. The amount of vitamin E given the rats was proportionately far in excess of what most human beings consume in their regular diet, or what is in a typical vitamin E supplement. But you should still be careful how much vitamin E you consume, cautions Dr. Bruce Bistrian, chief of clinical nutrition at Beth Israel Deaconess Medical Center and a professor of medicine at Harvard Medical School.

The U.S. Recommended Daily Allowance (RDA) for vitamin E is only 15 milligrams (mg), although many vitamin E supplements come in 400 mg doses, and the upper limit of what is considered a safe dose of vitamin E is 800 to 1000 mg per day. "More recent meta-analyses suggests that doses above 400 mg a day may be harmful," says Dr. Bistrian.

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