Q: How much Vitamin E should I take? Is natural Vitamin E any better than synthetic?
Vitamin E is a fat soluble vitamin that works as an antioxidant. An antioxidant helps protect your cells from damage by compounds called free radicals, which are produced by your body during metabolism. It was hoped that Vitamin E’s antioxidant action could decrease the risk of developing cancer, cataracts, heart disease and stroke, but in carefully designed clinical studies Vitamin E supplementation did not provide any benefit. In fact, Vitamin E supplementation was instead associated with an increased possibility of death, hemorrhagic stroke (stroke caused by bleeding into the brain) and prostate cancer.
How much Vitamin E do you need? According to the National Institutes for Health (the NIH), the recommended intake of Vitamin E for adults is 22.5 International Units (IU) daily. Although most Americans get about half that amount from their diet, Vitamin E deficiency is not very common. Vitamin E needs fat for it to be well absorbed, so eating a very low fat diet or having a disease that interferes with digestion or absorption of fat such as Crohn’s disease or cystic fibrosis can increase your risk of becoming deficient. Vitamin E deficiency may cause nerve and muscle damage with numbness in the arms and legs, muscle weakness, and vision problems. Vitamin E deficiency can also interfere with the effectiveness of your immune system.
Should you take a Vitamin E supplement? If most Americans get less than the recommended daily amount of Vitamin E in their diet, would taking it as a supplement make sense?
Most multivitamins include 30 IU of Vitamin E as alpha-tocopherol, which is considered 100% of the daily requirement for adults by the NIH. High dose Vitamin E supplements of 400 IU contain over 13 times that amount. The most common forms of Vitamin E are alpha-tocopherol and gamma-tocopherol. Gamma-tocopherol is found in foods rich in Vitamin E, with nuts, seeds, oils and green leafy vegetables such as spinach and broccoli the best sources.
Vitamin E as alpha-tocopherol exists in higher concentrations in the body than its cousin gamma-tocopherol, and until recently was assumed to be responsible for Vitamin E’s antioxidant effects. That may not be the whole story. Recent research has uncovered evidence that the key to the antioxidant potency of Vitamin E is the level of gamma-tocopherol, not the amount of alpha-tocopherol in the tissues and blood. Taking a supplement of alpha-tocopherol will actually decrease the level of gamma-tocopherol and suppress Vitamin E’s beneficial antioxidant action. This may explain why alpha-tocopherol supplements have produced negative instead of positive results in controlled research studies.
One study that found high dose Vitamin E supplementation to be helpful was the Age-Related Eye Disease Study, or AREDS. A formula of 5 vitamins and minerals including Vitamin E 400 IU was used in the 5 year study. In the most severely affected study participants, the AREDS formulation of Vitamins A, C and E combined with zinc and copper showed a 25% decrease in the progression of age-related macular degeneration (AMD), a common cause of blindness in the elderly. Those with mild or no AMD did not notice any benefit, however.
Most Vitamin E supplements contain alpha-tocopherol as either the natural form (d-alpha-tocopherol) or synthetic form (dl-alpha tocopherol). The main difference between them is their potency. The natural (d-alpha-tocopherol) form is 1.5 times as potent as the synthetic (dl- alpha-tocopherol) form. Gamma-tocopherol Vitamin E supplements are now available but it’s too early to know if they can prevent cancers, stroke or heart disease where the alpha-tocopherol form could not.
Unless you have age-related macular degeneration, taking a specific Vitamin E supplement is not only unnecessary but can cause bleeding problems, especially if you already take a blood thinner like warfarin, aspirin, or clopidogrel (Plavix®). For More information about Vitamin E is available at http://ods.od.nih.gov/factsheets/VitaminE-QuickFacts.
