Vitamin E benefits — and the risks of taking a supplement

Although it may not have the same high profile as some other vitamins, such as C and D, vitamin E has certainly enjoyed its time in the sun.

As an antioxidant, vitamin E — which is in foods such as seeds, nuts and leafy greens — helps protect us from molecules called free radicals that can damage our cells. The body also uses vitamin E to bolster our immunity, so we can fend off disease.

“Vitamin E plays a role in monocyte production, which are large white blood cells that fight against viruses and harmful bacteria,” explains Julie Stefanski, a registered dietitian for Stefanski Nutrition Services in York, Pennsylvania, and a spokesperson for the Academy of Nutrition and Dietetics.

Given its beneficial properties, vitamin E has long held promise as a possible prevention powerhouse. Initial research even seemed to suggest that taking the vitamin in supplement form could help ward off everything from cancer to heart disease. But other studies have found that taking vitamin E, especially in higher doses, is unhelpful and even potentially harmful — raising the risk of bleeding, stroke and, in some men, prostate cancer.

Not surprisingly, such mixed research results have given way to a more cautious, circumspect approach to vitamin E. Most experts now emphasize getting recommended levels of the vitamin through diet alone and don’t recommend vitamin E supplements for healthy individuals.

[READ: Everything You Need to Know About vitamin D]

Sources of vitamin E

“The recommended dietary allowance — the RDA — is 15 milligrams a day, and that’s for both males and females age 14 and over,” notes Hannah Kittrell, a registered dietitian and manager of the Mount Sinai PhysioLab, a nutrition and exercise physiology clinic in New York City. The dietary recommendations are slightly higher for women who are pregnant or breastfeeding, at 19 mg per day. Although, supplements aren’t routinely recommended for women who are pregnant or nursing either.

Vitamin E intake recommendations vary for kids, depending on their age. For example, 4 mg is considered adequate for infants 0 to 6 months. Vitamin E is a normal component of breast milk, and formula milk is also commonly enriched with the vitamin. Older children ages 9 to 13 should get 11 mg of vitamin E from food daily.

Experts roundly agree that vitamin E is safe and beneficial when consumed in food. Great natural sources include:

  • Wheat germ oil
  • Sunflower seeds
  • Almonds
  • Hazelnuts
  • Spinach
  • Sunflower, safflower, corn and soybean oil
  • Peanut butter and other nut butters

According to USDA data, a single tablespoon of wheat germ oil — which is extracted from the germ of wheat grain — is enough to meet the recommended daily allowance for vitamin E, with more than 20 mg of alpha-tocopherol, a form of the vitamin.

“While many seeds contain vitamin E, sunflower seeds are clearly the winner,” Kittrell said. Just a handful, or about 2 ounces, has enough vitamin E to meet the 15 mg RDA for vitamin E. Nuts and nut butters are also a great choice to get more vitamin E. Almonds, hazelnuts, pine nuts and peanuts are all good sources of vitamin E, she said. Vitamin E is also found in a range of other veggies and fruits, from avocado to kiwi.

Eating a well-balanced diet is a safe bet for increasing vitamin E intake. But experts say Western eating patterns that plate lots of processed foods (even though some like cereal are fortified in vitamin E) don’t meet the mark.

“When you talk about ‘What does the American diet look like?,’ we’re not eating nuts and seeds and really healthy oils and lots of fruits and vegetables,” said Maret Traber, a professor of nutrition science at the College of Public Health and Human Sciences at Oregon State University. “What we’re eating is lots of processed food,” said Traber, a principle investigator at OSU’s Linus Pauling Institute, where she runs a laboratory focused on vitamin E research. In

addition to governmental funding, like from the National Institutes of Health, her lab has received some support from DSM Nutritional Products in Switzerland, which produces vitamin E supplements.

Experts such as Traber say Americans simply aren’t doing enough to change their diets so that they get the nutrients, like vitamin E, that they need.

[See: How to Make Healthful Dietary Changes Last a Lifetime.]

Vitamin E supplements

Even though deficiency of vitamin E at a blood-level (called frank deficiency) isn’t common, most people still don’t get the recommended amount of vitamin E in their diet. Yet most don’t have a vitamin E deficiency that causes health problems. “Frank vitamin E deficiency is rare,” and overt symptoms of deficiency symptoms haven’t been found in healthy people who get little vitamin E in their diets, the NIH notes, based on past research.

Those with vitamin E deficiency can suffer from vision problems, muscle weakness, a degenerative disease of the nervous system called ataxia and impaired immune function, among other issues.

The naturally occurring vitamin is fat-soluble — that is to say, vitamin E is absorbed and stored by fat in our bodies. Certain medical conditions make it harder to absorb fat and therefore more likely a person may not absorb enough of the fat-soluble vitamin.

People at higher risk for developing a vitamin E deficiency include those with cystic fibrosis, which affects the digestive system, irritable bowel syndromes like Crohn’s disease, pancreatitis and celiac disease, an immune condition that can lead to damage in the small intestine if a person eats gluten (including wheat).

For those who have concerns that they may be vitamin E deficient, experts advise having a blood test done to check for deficiency. Then discuss with a doctor whether dietary changes and supplementation are warranted, as well as any potential benefits and risks associated with supplementation.

Side effects of too much vitamin E

Generally speaking, taking a vitamin E supplement if you’re healthy isn’t recommended.

For adults who do take a supplement, it’s advised that you not exceed 1,000 mg — or the equivalent of 1,500 IU (international units) — of vitamin E a day, which is what’s considered the tolerable upper intake level, or UL. That’s the maximum amount a person can take that’s unlikely to cause adverse health effects.

However, some studies indicate there may even be risks associated with taking less vitamin E. For example, while research suggests a vitamin E supplement may help protect against prostate cancer, particularly for men who smoke, other research indicates that taking 400 IU of vitamin E daily could increase prostate cancer. Similarly, some research suggests taking 400 IU of vitamin E daily could increase stroke risk.

It’s worth noting that much of the data comes from studying middle-aged and older patients, so it’s not entirely clear whether other factors, like having chronic disease or taking various supplements (besides just vitamin E), may have contributed to some of the increased risk patients faced. So the upper limit remains at 1,000 mg per day.

Still, experts urge taking a cautious approach with vitamin E supplementation in general. That means also talking with your doctor about any other supplements or medications you’re taking. For example, taking vitamin E if you’re on a blood thinner, including warfarin (Coumadin), clopidogrel (Plavix) or aspirin, could increase your risk of bleeding.

Water-soluble vitamins, such as vitamin C, aren’t stored in your body. Any excess is excreted in urine. In contrast, vitamin E is fat-soluble. This means any excess is stored in the body’s fat tissue and liver, so your body isn’t able to get rid of excess fat-soluble vitamins as quickly or readily. As such, it’s possible that if you take large doses of vitamin E over what’s recommended, it could accumulate in your body to toxic levels.

[See: The 12 Best Diets for Your Heart.]

Taking more vitamin E than recommended can increase the risk of serious side effects, including headache, blurry vision, fatigue or weakness and stomach cramps. Quit taking the supplement and call your doctor right away if you experience side effects.

Research sponsored by the National Eye Institute indicates vitamin E, taken with vitamin C, beta-carotene and zinc, slows the progression of age-related macular degeneration. And, generally speaking, vitamin E is known to protect cells in the eyes (as well as other cells in the body) from damage and therefore could help prevent vision loss. But the precise role this vitamin might play in prevention and management of a range of conditions still isn’t clear.

“Whether vitamin E can prevent cancer, heart disease, dementia, liver disease and stroke still requires further research,” according to the NIH. In the meantime, a safe bet is to improve your diet to get more of the antioxidant — something research has never shown to be harmful.

More from U.S. News

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Vitamin E Benefits — and Risks of Taking a Supplement originally appeared on usnews.com

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