Individuals who cannot absorb
fat may require a vitamin E supplement because some dietary fat is needed
for the absorption of vitamin E from the gastrointestinal tract. Anyone
diagnosed with cystic fibrosis, individuals who have had part or all of
their stomach removed, and individuals with malabsorptive problems such as
Crohn’s disease may not absorb fat and should discuss the need for
supplemental vitamin E with their physician. People who cannot absorb fat
often pass greasy stools or have chronic diarrhea.
Preliminary research has led
to a widely held belief that vitamin E may help prevent or delay coronary
heart disease. Researchers are fairly certain that oxidative modification of
LDL-cholesterol (sometimes called "bad" cholesterol) promotes blockages in
coronary arteries that may lead to atherosclerosis and heart attacks.
Vitamin E may help prevent or delay coronary heart disease by limiting the
oxidation of LDL-cholesterol. Vitamin E also may help prevent the formation
of blood clots, which could lead to a heart attack. Observational studies
have associated lower rates of heart disease with higher vitamin E intake. A
study of approximately 90,000 nurses suggested that the incidence of heart
disease was 30% to 40% lower among nurses with the highest intake of vitamin
E from diet and supplements. The range of intakes from both diet and
supplements in this group was 21.6 to 1,000 IU (32 to 1,500 mg), with the
median intake being 208 IU (139 mg).. A 1994 review of 5,133 Finnish men and
women aged 30 - 69 years suggested that increased dietary intake of vitamin
E was associated with decreased mortality (death) from heart disease.
Antioxidants such as vitamin
E help protect against the damaging effects of free radicals, which may
contribute to the development of chronic diseases such as cancer. Vitamin E
also may block the formation of nitrosamines, which are carcinogens formed
in the stomach from nitrites consumed in the diet. It also may protect
against the development of cancers by enhancing immune function. Some
evidence associates higher intake of vitamin E with a decreased incidence of
prostate cancer and breast cancer. A study of women in Iowa provided
evidence that an increased dietary intake of vitamin E may decrease the risk
of colon cancer, especially in women under 65 years of age.
Cataracts are growths on the
lens of the eye that cloud vision. They increase the risk of disability and
blindness in aging adults. Antioxidants are being studied to determine
whether they can help prevent or delay cataract growth. Observational
studies have found that lens clarity, which is used to diagnose cataracts,
was better in regular users of vitamin E supplements and in persons with
higher blood levels of vitamin E. The effects of smoking, a major risk
factor for developing cataracts, may override any potential benefit from the
vitamin E; it is always wise to quit smoking.
The health risk of too much
vitamin E is low. A recent review of the safety of vitamin E in the elderly
indicated that taking vitamin E supplements for up to four months at doses
of 530 mg or 800 IU (35 times the current RDA) had no significant effect on
general health, body weight, levels of body proteins, lipid levels, liver or
kidney function, thyroid hormones, amount or kinds of blood cells, and
bleeding time.
