General Description
Vitamin E is a member of the family of fat-soluble antioxidant nutrients
known as tocopherols. Alpha tocopherol is the most active of the
tocopherols in terms of vitamin E activity, but beta, delta, and
gamma tocopherols have antioxidant capabilities as well. Another
closely related group of compounds, the tocotrienols also exhibit
antioxidant properties. Many nutritionists recommend natural-source
supplements that include a mix of tocopherols and tocotrienols,
because these compounds are believed to complement each other's
activity. Supplemental vitamin E is available in natural and synthetic
forms, with the more potent, natural forms distinguished by a "d"
(d-alpha tocopherol) while synthetic forms are indicated by "dl"
(dl-alpha tocopherol).
Food sources
The best food sources of vitamin E include vegetable oils, nuts,
seeds, whole grains, and wheat germ. Other sources include asparagus,
avocado, green leafy vegetables, and tomatoes.
Health applications
Functions and uses
Vitamin E plays many vital roles in organs and systems throughout
the body, from the immune system to the brain, skin, eyes, liver,
and heart. As a fat-soluble nutrient, vitamin E is incorporated
into the lipid portions of cell membranes, where it helps protect
these structures from free-radical induced damage. As an antioxidant,
vitamin E helps protect LDL cholesterol molecules from oxidation,
which is especially beneficial for cardiovascular health. Oxidized
LDL is a major contributor to atherosclerosis, which can lead to
heart attack or stroke. Studies have shown that men and women who
supplement their diets with at least 100 IU of vitamin E per day
can significantly reduce their risk of heart disease.1,2
Dosage/toxicity
While the 15 IU per day RDA for vitamin E is sufficient to prevent
overt deficiency, the most commonly recommended dose of vitamin
E is 400 IU per day. Many dietary factors affect the body's vitamin
E requirements. A diet high in saturated fats increases vitamin
E requirements. Other nutrients like vitamin C and selenium can
increase the antioxidant potential of vitamin E. Vitamin E is
very safe, with adverse effects being rare even at doses as high
as 3,200 IU per day.3
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