Warn Patients About Possible Risks of Vitamin E Supplements

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Hello. I am Dr. Gerald Chodak from Medscape. Vitamins and over-the-counter supplements are back in the news with an updated report from the SELECT trial.^[1] This was a study that began in 2001 that enrolled patients over the next 3 years and assigned them to 1 of 4 groups: those who received placebo alone, vitamin E plus placebo, selenium plus placebo, or vitamin E plus selenium.

The results that were originally reported in 2008 found that there was no significant reduction in the development of prostate cancer in any of the 3 treatment groups. However, there was a trend toward a higher incidence of prostate cancer. The authors decided to continue following patients even after the study was discontinued.

After an additional 3 years of follow-up, the authors found a 17% higher incidence of prostate cancer in men taking vitamin E. It was muted or lessened in the men taking the combination of vitamin E and selenium, suggesting that selenium had some protective effect. This increase began as early as 3 years after the initiation of the trial and continued to increase.

The message is this: Not only did vitamin E not help to reduce the risk for prostate cancer, it actually increased the risk. This message is an important one to convey to our patients. With no prospective, randomized studies evaluating higher doses of supplements, there is really no way to tell whether there is any impact on disease prevention or treatment. Even more important, patients should realize that unless studied properly, we really do not even know the overall impact in terms of side effects.

Here we have yet another example of something that is over-the-counter that can actually cause harm. Patients should be alerted to that. Studies had previously suggested that vitamin E might be a heart-protective agent or may prevent other cancers. However, well-done studies have failed to demonstrate that.

I think it is important to find out from our patients whether they are taking vitamin E supplements and caution them about the increased risk for developing prostate cancer. We should discourage our patients from taking supplements that have not been studied properly. Most people do it thinking, "Even if it doesn't work, there's no harm."

Here is yet another example that harm can occur when tested properly. I look forward to your comments. Thank you.

Cite this: Gerald Chodak. Warn Patients About Possible Risks of Vitamin E Supplements - Medscape - Oct 28, 2011.

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