Vitamin E is a fat-soluble vitamin that helps protect your cells from damage. It does this by acting as an antioxidant. Antioxidants counteract the damage to your cells caused by compounds called free radicals, which are produced in your body during metabolism. Free radicals are very reactive compounds. They move around and interact with your cells in ways that can cause cancer, cataracts, heart disease or stroke.
With the 3 leading causes of death in America heart disease, cancer and stroke, there’s lots of interest in finding ways to decrease the risk of these, including reducing the negative effect free radicals have on your cells, either by generating fewer free radicals or increasing the antioxidant compounds available to counteract them.
Would supplementing with Vitamin E, an antioxidant, protect your cells and help reduce the incidence of these 3 top killers? Unfortunately, the results of carefully designed clinical studies clearly show that Vitamin E supplementation does not provide any clear benefit and in fact is associated with an increased likelihood of either dying, having a stroke caused by bleeding into the brain, or developing prostate cancer.
How much Vitamin E do you need? The National Institutes for Health (NIH) recommends that adults get 22.5 International Units (IU) of Vitamin E daily. Although most Americans get only 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 being deficient in Vitamin E. Vitamin E deficiency may cause nerve and muscle damage with numbness in your arms and legs, muscle weakness, vision problems and reduced effectiveness of your immune system.
Should you take a Vitamin E supplement?
There are 2 common forms of Vitamin E: alpha-tocopherol and gamma-tocopherol. 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. Most multivitamins include 30 IU of Vitamin E as alpha-tocopherol, considered to be 100% of the daily requirement for adults by the NIH. High dose Vitamin E supplements of 400 IU contain over 13 times that amount.
While alpha-tocopherol is found in vitamin supplements, gamma-tocopherol is found in foods rich in Vitamin E such as nuts, seeds, oils and green leafy vegetables such as spinach and broccoli.
Recent research has uncovered evidence that the key to the antioxidant potency of Vitamin E is the level of gamma-tocopherol in the tissues and blood, not the amount of alpha-tocopherol. Taking a supplement of alpha-tocopherol will actually DECREASE the level of gamma-tocopherol, suppressing 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 where Vitamin E supplementation helped is the Age-Related Eye Disease Study, or AREDS. In the 5-year study, a formulation of Vitamins A, C and E combined with zinc and copper including 400 IU of Vitamin E was used. The most severely affected study participants showed a 25% decrease in the progression of age-related macular degeneration (AMD), a common cause of blindness in the elderly. However, for those with mild or no AMD, there was no benefit.
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 cancer, stroke or heart disease where the alpha-tocopherol form could not.
Should you take a Vitamin E supplement?
- YES, if you have age-related macular degeneration. The AREDS formulation is proven to help, such as in PreserVision® AREDS. Another supplement recommended by eye care professionals is Ocuvite®. Ask your eye care professional which would be best for you.
- NO, if you are taking a blood thinner like warfarin (Coumadin®), aspirin or clopidogrel (Plavix®). Vitamin E supplementation can actually cause bleeding problems in high doses or in people who take blood thinners.
- The BEST way to get the antioxidant benefits of Vitamin E is to eat plenty of green leafy vegetables such as spinach and broccoli.
There’s more information about Vitamin E at http://ods.od.nih.gov/factsheets/VitaminE-QuickFacts.
