Easy does it with vitamin E - Harvard Health

Published: March, 2014

Swallowing an amber-colored vitamin E capsule has long been a daily ritual for millions of American women. It may be time to stop.

Today vitamin E is one of the most widely used supplements, taken regularly by nearly a quarter of adults ages 55 and over. Its popularity derives from studies over the years suggesting that vitamin E's antioxidant properties could help stave off common age-related ills, such as heart disease, cancer, and cataracts. Many health care professionals were personally on board, taking the supplement as well as recommending it. Although there was no proof of its effectiveness, the consensus was, "It might help, and it couldn't hurt."

But analysis suggests that vitamin E supplementation might not be as harmless as everyone was assuming. Researchers pooled and examined the results of 19 clinical trials published between 1966 and 2004 involving nearly 136,000 people who took vitamin E for one reason or another. They found that the overall risk of dying was greater for people who took 400 IU (the amount found in a typical vitamin E capsule) or more daily, compared to those who took lower doses (Annals of Internal Medicine, Jan. 4, 2005). And the risk of dying rose with increasing doses above 150 IU per day.

This study does have some drawbacks. In the 19 trials it analyzed, people using doses of 400 IU or more were largely older adults with chronic diseases. So the findings don't necessarily apply to younger, healthy adults. Also, in 10 of the 19 trials, people took other nutritional supplements as well, making it hard to single out vitamin E as the sole culprit. Finally, the amount of increased risk was very small. And in those taking doses of 150 IU per day or less, the risk of death from all causes was actually lower. Thus, some experts aren't convinced there's any increased risk, despite what was found in this study.

Nevertheless, the research confirmed a trend in expert opinion. This once-lauded vitamin has been losing its luster among nutrition experts for some time. Until 2003, for example, students who took the "Preventive Medicine and Nutrition" course at Harvard Medical School were assigned to argue the wisdom of recommending vitamin E to patients. "But we dropped vitamin E as a debate topic," says HWHW advisory board member Dr. Helen Delichatsios, because recent data overwhelmingly show that vitamin E is not useful. What happened, and what does it mean for you? First, some background.

The many faces of vitamin E

Vitamin E occurs in eight different forms. Those most commonly found in foods and supplements are d-alpha-tocopherol — the synthetic form is d,l-alpha-tocopherol — and gamma-tocopherol. Synthetic alpha-tocopherol is only half as active in the body as the natural form. Certain supplements, labeled "mixed tocopherols," contain various other natural forms, including beta- and delta-tocopherol. Some research suggests that gamma-tocopherol may have unique anticancer effects, but the evidence is far from conclusive.

For women, the recommended dietary intake of vitamin E is 15 milligrams (mg) per day. That's the equivalent of 22.5 international units (IU), the designation used on many supplement labels. Most multivitamins contain 22–30 IU of vitamin E, whereas vitamin E–only capsules may contain anywhere from 100 to 800 IU (or higher).

Who needs a vitamin E supplement? According to one recent large survey, the average woman falls a little short, consuming only about 8.4 mg (12.6 IU) per day in food. But that may not be accurate. An Institute of Medicine study indicates that many people underreport the amount of fat and calories they actually consume, including fats and oils used in cooking — a significant source of vitamin E. Deficiencies of vitamin E are uncommon, except in people with unusual health problems, such as difficulties with fat absorption or rare genetic disorders. It's also possible that a person on a very low–fat diet might be deficient.