|
| |
Vitamin E (d-alpha tocopherol) Information
By: Dr. Obikoya
Vitamin E is a fat soluble antioxidant vitamin that
helps to neutralize potentially damaging free radicals in our body. It exists in
eight different forms, d-alpha-tocopherol being the most active form and one of
the most powerful biologically active antioxidant. Each form has a different
level of potency (functional use) in the body. The tocopherol and tocotrienol
subfamilies are each composed of alpha, beta, gamma and delta vitamins having
unique biological effects, with generally declining activity; e.g. delta is far
less active than the alpha form.
As a supplement, Vitamin E has a number of health benefits for the body. Vitamin
E is particularly important for the protection of our cell membranes as well as
keeping your skin, heart and circulation, nerves, muscles and red blood cells
healthy. Antioxidants such as vitamin E protect your cells against the effects
of free radicals, potentially damaging by-products of your body’s metabolism.
Free radicals can cause cell damage that may lead to the development of
cardiovascular disease and cancer.
One or more members of the vitamin E family may also reduce cellular aging,
inhibit the potentially damaging peroxynitrite radical, inhibit melanoma cell
growth, prevent abnormal blood clotting, synergize with vitamin A to protect the
lungs against pollutants, protect nervous system and retina, lower the risk of
ischemic and coronary heart disease, lower the risk of certain kinds of cancer,
protect immune function and reduce the risk of Alzheimer’s disease,
particularly if high doses are taken in combination with vitamin C.
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
you against the development of cancers by enhancing immune function. Some
evidence links higher intake of vitamin E with a decreased incidence of prostate
cancer and breast cancer.
Gamma tocopherol is only 10 to 30% as strong as alpha tocopherol, yet recent
studies have shown it to be essential for maintaining the health of our cell
membranes, especially if alpha tocopherol is being supplemented. New studies
continue to elucidate the unique benefits of individual members of the vitamin E
family. For example, tocotrienols have been shown to lower cholesterol, prevent
LDL oxidation, and reduce atherosclerotic plaque formation more effectively than
tocopherols. For these and other reasons, the original definition of vitamin E
now includes all eight family members and the related compounds that convert to
them in the body.
Cataracts, growths on the lens of our eye that cloud vision, increase the risk
of disability and blindness in aging adults. Antioxidants may prevent or delay
cataract growth. Studies have shown 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.1
100 IU or more of supplemental vitamin E a day has been shown to reduce the risk
of heart attacks in healthy people. If you have pre-existing coronary artery
disease it is recommended you take 800 to 1600 IU a day of Vitamin E. Vitamin E
also may help prevent the formation of blood clots, which could lead to a heart
attack. Studies have linked lower rates of heart disease with higher vitamin E
intake.
Low-fat diets can substantially decrease vitamin E intakes if food choices are
not carefully made to enhance alpha-tocopherol intakes. If you are taking
anti-clotting medication, consult with your doctor before taking Vitamin E.
Ingestion of total vitamin E products in excess of 1200 IU daily may interfere
with absorption and metabolism of vitamins A and K.
Abetalipoproteinemia is a rare inherited disorder of fat metabolism that results
in poor absorption of dietary fat and vitamin E Individuals with
abetalipoproteinemia may be prescribed special vitamin E supplements by a
physician to treat this disorder.
Some prefer cold-water dispersible dry powder vitamin E supplements in the form
of alpha tocopheryl succinate or acetate because the cold-water dispersible
forms are efficiently absorbed even when taken on an empty stomach or with a
low-fat meal. Note that the non-cold water dispersible (oil) forms of vitamin E
may be poorly absorbed unless taken with several grams of fats or oils.
Cold-water dispersible vitamin E is twice as expensive as soybean oil E-acetate,
but (no surprise here) the cold-water dispersible forms are more efficiently
absorbed. It is important that you know how well the vitamin E you are about to
buy absorbs into the bloodstream. Cold-water dispersible vitamin E, whether in a
succinate or acetate form, always comes in a white dry powder, while noncold-water
dispersible natural and synthetic acetate forms of vitamin E are always in thick
brown oil.
Vitamin E deficiency is rare in humans although likely to occur under certain
specific situations namely, when an individual cannot absorb dietary fat, was
born premature, is a very low birth weight infants (birth weights less than 1500
grams, or 3 1/2 pounds), and in individuals with rare disorders of fat
metabolism . A vitamin E deficiency is usually characterized by neurological
problems due to poor nerve conduction. The greater problem by far is not a gross
deficiency but low vitamin E levels over many decades.
Vitamin E is one of the most beneficial vitamins for you. It is important that
you take it or find a way to obtain it through foods daily to ensure that you
derive the most benefit from this all-important vitamin. This is more so if you
cannot absorb fat or are on a low fat diet as some dietary fat is needed for the
absorption of vitamin E from the gastrointestinal tract. You will also need
additional vitamin E supplements if you are diagnosed with cystic fibrosis, have
had part or all of your stomach removed, or have malabsorption problems such as
Crohn’s disease. People who cannot absorb fat often pass greasy stools or have
chronic diarrhea, called steatorrhea.
|