Vitamin E supplements and prostate cancer risk in healthy men
What it found
In a large trial of healthy men, those who took vitamin E supplements had a higher rate of prostate cancer than those who took a placebo.
The increase was small but the authors say it was not likely due to chance.
What they found
Studies in people
Prostate cancer risk
Men who took vitamin E alone had a higher rate of prostate cancer than those on placebo. The difference became apparent during the third year and grew slightly each year after.
Selenium and combination
The selenium alone and selenium plus vitamin E groups also had slightly more prostate cancers than placebo, but the differences were not statistically significant.
Absolute risk increase
Compared with placebo, the extra number of prostate cancer cases per 1,000 person-years was 1.6 for vitamin E, 0.9 for selenium, and 0.4 for the combination.
Aggressive cancer
The risk of Gleason 7 or higher prostate cancer was higher in all three supplement groups, but the differences did not reach statistical significance.
Other health outcomes
There were no significant differences between groups in overall survival, lung cancer, colorectal cancer, other cancers, deaths, or serious cardiovascular events.
Type 2 diabetes
The earlier signal of increased type 2 diabetes in the selenium group became weaker with longer follow-up and was not statistically significant.
What the authors conclude
“Dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men.”
Also in their conclusions
- They conclude that dietary supplementation with vitamin E significantly increased the risk of prostate cancer among healthy men.
- They advise that caution should be used when recommending or studying high doses of micronutrients.
- They state that consumers should be skeptical of health claims for unregulated over-the-counter products in the absence of strong evidence of benefit from clinical trials.
How it was done
Earlier lab and population studies suggested that selenium and vitamin E might lower the risk of prostate cancer. The authors ran this trial to test whether these supplements could prevent prostate cancer in men at average risk.
They randomly assigned 35,533 men from 427 sites in the United States, Canada, and Puerto Rico to one of four groups: selenium alone, vitamin E alone, both, or placebo. The men took the supplements or placebo for a planned follow-up of at least 7 and up to 12 years. The main outcome was whether they developed prostate cancer.
What it can’t tell you
- This trial was in men at average risk of prostate cancer, so the results may not apply to other groups.
- The trial cannot show why vitamin E might increase prostate cancer risk; the authors say a biological explanation is not apparent from these data.
Who paid
- Funding
- Funded by NCI NIH HHS (from the PubMed record).
- Authors work at
- Glickman Urological and Kidney Institute, USA
The paper
- Title
- Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT)
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Klein EA, Thompson IM, Tangen CM, et al (2011). Vitamin E and the risk of prostate cancer: the Selenium and Vitamin E Cancer Prevention Trial (SELECT). JAMA. doi:10.1001/jama.2011.1437Free full textPubMed 21990298DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error