Vitamin E: One Case in Which the Hype May Be True

Vitamin E has received an enormous amount of publicity in the last few years, and a lot of it has been based on pretty solid scientific evidence. Of course, when even the most well-researched and useful of substances becomes a highly marketable commodity, greed often outruns science, and suddenly the claims are flying faster than the proverbial speeding magic bullet.

Although our position on most supplements has been a cautionary one, this is a case in which the hype is probably not too far from the truth. Nonetheless, it can all be a bit overwhelming. In case you are confused, here’s some basic information on vitamin E.

* What is vitamin E?

Despite its name, vitamin E doesn’t function in the same way as other vitamins (as a co-factor for enzymatic reactions), and a deficiency of it does not generally cause the rapid onset of diseases like scurvy (deficiency of vitamin C) or rickets (deficiency of vitamin D). Instead, vitamin E’s primary job is to serve as an antioxidant; inadequate intake is usually manifested in chronic, degenerative diseases such as cancer, atherosclerosis and heart disease, which take decades to develop.

Vitamin E is actually not one but eight related compounds. Four of them are called tocopherols (alpha, beta, gamma and delta), and the other four are called tocotrienols. Of all these, the ones called d-alpha tocopherols are the most available to the body.

While the synthetic forms of most vitamins are pretty much equivalent to the natural vitamins, vitamin E is an exception. In fact, there are actual chemical differences between natural and synthetic forms. It turns out that natural vitamin E is much better absorbed and retained than the synthetic version, and about twice as much ends up in the bloodstream. One way to tell the difference is that synthetic capsules are labeled “dl-alpha tocopherol.” Natural vitamin E will be called d-alpha tocopherol or mixed tocopherols.

* What can vitamin E do?

As a fat-soluble antioxidant, vitamin E is one of the body’s most important defenses against free-radical damage. Free-radical damage to cells has been linked to various forms of cancer, coronary heart disease, premature aging, cataract formation and arthritis. Ongoing research is also looking at vitamin E’s potential effect on boosting the immune system, relieving nighttime leg cramps, easing PMS and protecting people with high blood lipid levels. Some of the strongest evidence concerns the protective effect vitamin E seems to have for coronary artery disease.

* What is the recommended daily allowance, or RDA, for vitamin E?

The RDA for vitamin E is quite low: 8 to 10 milligrams a day. However, most experts now agree that an optimal amount is more likely between 133 and 533 milligrams (200-800 international units, or IU) a day. Eating a balanced diet can almost certainly provide the RDA, but it is hard to get such larger amounts from foods, especially if you are consuming a low-fat diet. For many people, taking supplements is the only way to get enough.

Fortunately, larger doses (200 to 800 IU) don’t seem to produce serious side effects, although people taking blood-thinning drugs (anticoagulants) should check with their doctor before taking supplements at this level.

* What foods contain vitamin E?

The richest food sources of vitamin E are vegetable oils, nuts and whole grains. The dietary mother lode of vitamin E is wheat germ oil, with 119 milligrams (178 IU) per 3 1/2 ounces. However, this is not necessarily something that you might normally have in the pantry, and 3 1/2 ounces is a lot of oil. Some more manageable food sources and amounts include:

* Corn or soybean oil: 1 tablespoon has 12 milligrams.

* Canola or sunflower oil: 1 tablespoon, 8 milligrams.

* Kale, cooked: 1 cup, 7 milligrams.

* Wheat germ: 1 ounce, 4 milligrams.

* Almonds, hazelnuts or sunflower seeds: 1 ounce, 4 milligrams.

* Spinach, cooked: 1 cup, 4 milligrams.

* Asparagus, cooked: 4 ounces, 3 milligrams.

* Blueberries: 1 cup, 3 milligrams.

* Broccoli, chopped, cooked: 1 cup, 2 milligrams.

Finally, we would like to change the format of this column from time to time and provide answers to specific questions posed by our readers. If you have a question related to food and health, please send it to us in one of the following ways:

Mail: Dale Ogar, Eating Smart, School of Public Health, University of California, Berkeley, CA 94720-7360.

E-mail: daogar@uclink4.berkeley.edu.

Fax: Attention: Dale Ogar, (510) 642-2857.

We can’t promise to answer all your questions, but we will do the best we can.