What is vitamin E?
Also known as tocopherol or alpha-tocopherol, vitamin E is a fat-soluble
vitamin stored in the liver. It is one of three vitamins which also act
as antioxidants.
Why do we need it?
In its role as an antioxidant, vitamin E helps neutralize unstable particles
called free radicals which damage cell membranes. It also inhibits the
oxidation of LDL cholesterol ("bad" cholesterol), which may
reduce the risk of arterial plaque buildup, stroke and heart attacks.
In addition, vitamin E plays an important function in the formation of
red blood cells and the use of vitamin K. Some studies have shown that
vitamin E may raise one's resistance to infectious diseases and protect
against cataracts.
How much vitamin E should I take?
According to the National Academy of Sciences, the recommended daily
allowance for vitamin E (alpho-tocopherol) is as follows:
- Adult men: 10 milligrams/day
- Adult women: 8 milligrams/day
- Children aged 7-10: 7 milligrams/day
- Infants: 4 milligrams/day
- Pregnant/lactating women: 12 milligrams/day
In addition to the NAS guidelines, some groups recommend much higher
doses (between 70-130 milligrams/day).
What are some good sources of vitamin E?
Vitamin E is found in vegetable oils (most notably wheat germ oil), sweet
potatoes, avocados, nuts, sunflower seeds and soybeans. Smaller amounts
are found in egg yolks and green leafy vegetables.
What can happen if I don't get enough vitamin
E?
Deficiencies of vitamin E have been linked to heart disease. People with
extremely low blood levels of vitamin E may be also be at higher risk
for cancer.
What can happen if I take too much?
Some people taking massive amounts of vitamin E have reported experiencing
fatigue, nausea and diarrhea. Too much vitamin E may also cause bleeding
problems, particularly in people taking anti-clotting medications.
References
- Horwitt MK. Therapeutic uses of vitamin E in medicine.
Nutrition Reviews March 1980;38(3):105113.
- Horwitt MK. Data supporting supplementation of humans
with vitamin E. Nutrition 1991;121:42429.
- Rimm EB, Stampfer MJ, Ascherio A, et al. Vitamin E
consumption and the risk of coronary heart disease in men. N Engl
J Med 1993;328:145056.
- Stampfer MJ, Hennekens CH, Manson JE, et al. Vitamin
E consumption and the risk of coronary heart disease in women. N
Engl J Med 1993;328:144449.
- Stephens NG, Parsons A, Schofield PM, et al. Randomised
controlled trial of vitamin E in patients with coronary disease: Cambridge
Heart Antioxidant Study (CHAOS). Lancet 1996;347:78186.
- Christen S, Woodall AA, Shigenaga MK, Southwell-Keely,
Duncan MW, Ames BN. Gamma-tocopherol traps mutagenic electrophiles such
as NO+ and complements alpha-tocopherol: physiological implications.
Proc Natl Acad Sci 1997;94:321722.