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By Thomas Saphner, MD, FACP – Green Bay Oncology
Principal Investigator, St. Vincent Regional Cancer Center

More is not always better.

Breaking news from the Journal of the American Medical Association (JAMA) is that Vitamin E supplements are associated with an increased risk of prostate cancer. These surprising findings are from an extensive trial prompted by information that suggested Vitamin E, or a mineral, selenium, might help prevent prostate cancer.

Thirty-five thousand men across the U.S. volunteered to participate in the trial, including 105 men from the Green Bay area. The goal of the trial was to provide definitive results that two previous trials did not:

1) The Alpha Tocopherol, Beta Carotene (ATBC) trial that suggested that Alpha Tocopherol, another name for vitamin E, may decrease prostate cancer; and

2) The Physicians Health Study II that suggested Vitamin E had no effect on prostate cancer.

Instead, the latest findings, as reported in JAMA, suggest that Vitamin E may actually cause a slight increase in prostate cancer.

“Given that more than 50% of individuals 60 years of older are taking supplements containing Vitamin E and that 23% of them are taking at least 400 IU/day despite a recommended daily dietary allowance of 22.4 IU for adult men, the implications of our observations are substantial,” say the authors of the paper.

If nothing else, the study suggests that people should not take supplementary Vitamin E that exceeds recommended daily dietary allowances.

“The lack of benefit from dietary supplementation with Vitamin E or other agents with respect to preventing common health conditions and cancers, or improving overall survival and their potential harm, underscore the need for consumers to be skeptical of health claims for unregulated over-the-counter products in the absence of strong evidence of benefit demonstrated in clinical trials,” the trial authors go on to say.

Other high-dose vitamin trials have also suggested harm with vitamin supplements. For example, high doses of beta-carotene have been associated with a greater risk of lung cancer in two trials, and high-dose folate has been associated with an increased risk of colon polyps.  All of these studies “suggest that caution should be used in recommending or studying high doses of micronutrients” say
the authors of the vitamin E trial.

Many people ask their doctors about the best dietary supplements to take, and most are genuinely surprised when they learn that doctors generally do not recommend vitamins, minerals, or other processed supplements. Doctors know that supplements do not replace a healthy diet that includes fruits, vegetables, and other food sources that provide daily-recommended nutrients. This is not to say that supplements cannot have a healthful effect for specified patients and circumstances. But, today, as retail store aisles are filled with supplemental options and promises, it is important to remember this timeless adage: Buyer beware.

Vitamin E may or may not cause prostate cancer, but there is no evidence that it prevents prostate cancer. My advice to patients, family and friends is DON’T take it.

A final note on the Vitamin E and selenium trial as it relates to study participants. All stopped participation on October 23, 2008, when the study closed, and all participants have, or will, receive a letter informing them of these just-published study results.

– October 2011