The Truth About Vitamin E

The Truth About Vitamin E

The Annals of Internal Medicine recently published an article stating that taking 400 IU or more of vitamin E every day is detrimental to your health. It was associated with an increase in mortality compared with people not taking this amount of vitamin E. What is your opinion, and is it a cause for concern?

There is absolutely no cause for concern if you are a normally healthy person, or, in all likelihood, even if you are not. Vitamins are natural substances found within the human body and throughout the food supply; they are essential for life. And of all the vitamins, vitamin E is one of the best researched. In many hundreds of clinical studies, it has been found to help protect against free radicals?destructive substances that have been clearly associated with heart disease and cancer. As well, many hundreds of other studies have shown a wide array of benefits, including:

Vitamin E boosts the immune system
Vitamin E improves vision by helping prevent cataracts and macular degeneration
Vitamin E enhances brain function; it enhances short-term memory and even reduces the risk of Alzheimer¡¯s disease
Vitamin E helps prevent respiratory infections in the elderly
And much more

We are warranted by the abundance of these and other studies to say that the safety of vitamin E is very high. Moreover, to the best of our knowledge, there has never been a study showing any significant side effects from vitamin E. In fact, the Institute for Medicine?a private, nongovernmental organization?has performed studies for various health branches of the U.S. government and found that the consumption of vitamin E is without any problems at intakes as high as 1600 IU/day. Hoffman-La Roche has reported that there is a solid body of literature demonstrating that these and much higher vitamin E intakes are safe.1 According to Lawrence Machlin, former director of the Department of Clinical Nutrition at that company, and a principal vitamin E researcher himself, the company had done studies showing little toxicity at the staggering amount of 65,000 IU/day.

Yet what are we to make of the meta-analysis on vitamin E and all-cause mortality just published in the Annals of Internal Medicine, which showed a slight increase in deaths for a small segment of a select population?2 First off, the results represent a skewed section of the population, i.e., people who were already at grave risk from existing diseases, including cancer, heart disease, Alzheimer¡¯s, Parkinson¡¯s, and kidney failure. It is extremely irresponsible to draw conclusions for the whole population based on a combination of studies consisting of subjects already afflicted with life-threatening illnesses.

Second, only one of 19 studies selected for inclusion in the meta-analysis showed any negative correspondence. In the words of the authors, the findings were limited because ¡°¡¦ the generalizability of the findings to healthy adults is uncertain. Precise estimation of the threshold at which risk increases is difficult.¡±

Don't be misdirected about vitamin E.

Nevertheless, this did not prevent them from making far-reaching generalizations about vitamin E usage and all-cause mortality for the entire population, without providing any evidence that negative effects would occur in healthy populations. Corralling numerous clinical trials into one large cohort may have given the conclusions greater statistical power, but the authors failed to examine the limitations of each separate study.

It is interesting to note that benefits were attributed to vitamin E in many of the other 18 studies, but the authors made little of this. For example, one study showed that 400 and 800 IU/day of vitamin E reduced the risk of heart attack by 75% in men already manifesting symptoms of heart disease. Another study found that 400 IU of vitamin E, along with other nutrients, could reduce the risk for the leading cause of blindness in elderly people: age-related macular degeneration. And another study found that 800 IU of vitamin E could reduce the risk of heart attacks and of death from heart disease in people with kidney failure. Also worth noting is that yet another study showed that a very high dose of vitamin E (2000 IU) delayed the progression of Alzheimer¡¯s disease. And none of these studies showed any correspondence with increased mortality.

Said John Hathcock, Ph.D., Vice President of Scientific & International Affairs at the Council for Responsible Nutrition (who once served as a senior scientist at the FDA, in charge of determining the safe levels of supplements), ¡°This is an unfortunate misdirection of science in an attempt to make something out of nothing for the sake of headlines.¡±

Finally, it is crucial to note that the study does not suggest that vitamin E was the cause of death among the subjects?who, remember, were already afflicted with life-threatening illnesses.

Weber P, Bendich A, Machlin LJ. Vitamin E and human health: rationale for determining recommended intake levels. Nutrition 1997 May;13(5):450-60. [Review]
Miller ER III, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E. Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med 2005 Jan 4;142(1). (In press)