Vitamin E (also called alpha-tocopherol) shares top billing with Vitamin C as the most popular and most often used vitamin. Results of research in the early 1990s suggest that Vitamin E defends against the ill effects of smog, smoking, and sun, and that it might prevent certain cancers and aging of the skin. Other studies show that it strengthens the immune system, staves off cataracts, and could help slow the progression of AlzheimerÕs disease. Vitamin E, a fat-soluble nutrient, can boost the immune system so that it fights off common old-age illnesses better.
Two studies published in the New England Journal of Medicine by Harvard researchers shows that in studies of over 127,000 health professionals, those who took large doses of Vitamin E had a 40% lower risk of heart disease. Experts believe that Vitamin E accomplished this by inhibiting the oxidation of free radicals. Excessive amounts of these essential compounds tend to oxidize and destroy human cells.1 It must be noted that no evidence exists that taking Vitamin E supplements over a lifetime is safe.
The term Vitamin E applies to a family of eight related compounds, the tocopherols and the tocotrienols. The four major forms of Vitamin E are designated alpha, beta, delta, and gamma, on the basis of the chemical structure. The tocotrienols are less widely distributed in nature than the tocopherols, although they are present in palm oil. Tocotrienols may have biological activity comparable with that of the tocopherols but were once considered of less nutritional importance.2 Alpha-tocopherol, commonly known as Vitamin E, is the form found most in nature and the most biologically active. Besides its role as an antioxidant, it is important in the synthesis and maintenance of red blood cells and their constituents, and might have a direct effect on the synthesis of hemoglobin.
Vitamin E is an antioxidant that also profits from its interaction with other antioxidants, like Vitamin C and selenium. As an antioxidant, it stabilizes membranes and protects them against free radical damage; protects the lungs against damage from air pollutants; prevents tumor growth; protects tissues of the skin, eye, liver, breast and calf muscle; maintains the biological integrity of Vitamin A and increases the bodyÕs stores of this vitamin.
Vitamin E and other antioxidants satiate free radicals, stabilizing them before they harm cells. Vitamin E is carried through the blood stream in particles of low-density lipoprotein (LDL), or "bad" cholesterol. By blocking the oxidation of LDL, experts believe Vitamin E can prevent it from infiltrating cells and clogging arteries. Although the results of the Harvard studies were impressive, they demonstrated only an association between the vitamin and reduced risk of heart disease, not a cause-and-effect relationship.
Of all the antioxidants, Vitamins E so far has been the most consistent, even strongest, performer. According to a 1995 issue of Postgraduate Medicine, the results of human studies on all antioxidants but Vitamin E are variable. The NursesÕ Health study of over 87,000 women found that Vitamin E supplements helped prevent coronary artery disease, but that no benefit was derived from Vitamin C or beta carotene. The Health Professionals Follow-up study of nearly 40,000 men also found Vitamin E to be beneficial, as was beta carotene in smokers, but no benefit was found for Vitamin C. Other studies found Vitamin C and other antioxidants to be important and more consistently beneficial, but they fell shy of the success of Vitamin E.
Weighing all this evidence, investigators at the Alton Ochsner Clinic in New Orleans have argued current data supports the use of antioxidant vitamins (particularly Vitamin E) in patients with known atherosclerosis or with a very high risk of developing it. However, they add, this therapy does not substitute for vigorous risk factor modification, including improving lipid levels, reducing blood pressure, stopping smoking, losing weight, and exercising regularly. In 1993, a clinical trial to compare the effects of Vitamin E versus a placebo got underway, but it may take years before the results are known.
Some experts fear that if people are encouraged to take Vitamin E, they may abandon healthy habits such as exercise and a low-fat diet. Advocating Vitamin E supplements goes against what nutritionists have been preaching for years Ñ that one can get everything one needs to stay healthy in a well-balanced diet. Meanwhile, though, a survey has shown that many Vitamin E experts are themselves taking Vitamin E supplements.
1 Stampfer et. al, New England Journal of Medicine, May 1993.
2 Ziegler E. and Filer, L.J., Present Knowledge in Nutrition, Seventh Edition, 130.
VITAMIN E: SOURCES
Available as:
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: PROVEN BENEFITS
What this vitamin does:
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: UNPROVED SPECULATED BENEFITS
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: SPECIAL CONSIDERATIONS
Miscellaneous information:
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: DEFICIENCY SYMPTOMS
Premature infants and children:
Adults:
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: UNPROVED SPECULATED SYMPTOMS
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: LAB TESTS TO DETECT DEFICIENCY
Blood tocopherol level
Excess creatine in urine to indicate muscle breakdown
Red blood cell fragility test1
1 From Griffith HW, Vitamins, Minerals, and Supplements.
VITAMIN E: OPTIMAL LEVELS
200-800 IU
VITAMIN E: MINIMUM DOSAGE
Recommended Dietary Allowance (RDA):
Estimate of adequate daily intake by the Food and Nutrition Board of the National Research Council, 1989.
Age RDA
0-12 months 3-4mg
1-10 years 6-7mg
MALES
11+ years 10mg
FEMALES
11+ years 8mg
Pregnant 10mg
Lactating 1st 6 mos 12mg
2nd 6 mos 11mg
Note: Labels may list as mg or IU. 1 mg synthetic = 1 IU. 1 mg natural = 1.3 IU.
VITAMIN E: WARNINGS AND PRECAUTIONS
Don't take if you:
Consult your doctor if you have:
Over age 55:
Pregnancy:
Breast-feeding:
Storage:
1 From Griffith HW, Vitamins, Minerals, and Supplements.
Signs and symptoms:
Very high doses (over 800 units/day) causes altered immunity, impaired sex functions, increased risk of blood clots, altered metabolism of thyroid, pituitary and adrenal hormones.
What to do:
For other symptoms of toxicity: Discontinue vitamin, and consult doctor. Also see ADVERSE REACTIONS OR SIDE EFFECTS.1
1 From Griffith HW, Vitamins, Minerals, and Supplements.
Reaction or Effect What to do
Abdominal pain Discontinue. Call doctor immediately.
Breast enlargement Discontinue. Call doctor when convenient.
Diarrhea Discontinue. Call doctor immediately.
Dizziness Discontinue. Call doctor when convenient.
Flu-like symptoms Discontinue. Call doctor immediately.
Headache Discontinue. Call doctor when convenient.
Nausea Discontinue. Call doctor immediately.
Tiredness or weakness Discontinue. Call doctor when convenient.
Vision blurred Discontinue. Call doctor immediately.1
1 From Griffith HW, Vitamins, Minerals, and Supplements.
Antacids decreases Vitamin E absorption.
Anti-coagulants, coumarin- or indandione-type (blood thinners), may increase spontaneous or hidden bleeding.
Cholestyramine may decrease absorption of Vitamin E.
Colestipol may decrease absorption of Vitamin E.
Vitamin E decreases effect of iron supplement in people with iron-deficiency anemia. Iron supplements decrease Vitamin-E effect in healthy people.
Mineral oil may decrease absorption of Vitamin E.
Sucralfate may decrease absorption of Vitamin E.
Vitamin A facilitates absorption, storage and utilization of Vitamin A. Reduces potential toxicity of Vitamin A. Excessive doses of Vitamin E causes Vitamin A depletion.
Tobacco decreases absorption. Smokers may require supplemental Vitamin E.
Chronic alcoholism depletes Vitamin E stores in liver.1
1 From Griffith HW, Vitamins, Minerals, and Supplements.
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