Safety check
Vitamin E and Prostate Cancer Risk: The SELECT Trial
Vitamin E and prostate cancer are linked in one large trial. In SELECT, men taking 400 IU a day of synthetic vitamin E had a 17% higher risk of prostate cancer than men on placebo. Protoflow lists 13 mg of vitamin E, about 19 IU in natural form, a small fraction of that dose. The trial did not test small amounts.
Written by the Protoflow label deskUpdated · 4 min read
What did the SELECT trial find about vitamin E?
The SELECT trial found more prostate cancers in men taking vitamin E than in men taking placebo. It was a randomized trial of 34,887 men, given selenium, vitamin E, both or placebo for several years (Klein et al., JAMA 2011 (SELECT)).
Prostate cancer appeared in 529 men on placebo and 620 on vitamin E, a hazard ratio of 1.17. That works out to 1.6 extra cases per 1,000 person-years. Selenium alone and the pair together showed no significant difference.
The trial was built to test cancer prevention, and it did not find protection. It found a small added risk instead.
| Group | Result vs placebo |
|---|---|
| Vitamin E 400 IU | 17% higher risk (hazard ratio 1.17) |
| Selenium alone | Not significantly different |
| Selenium plus vitamin E | Not significantly different |
How does the SELECT dose compare with Protoflow?
The SELECT dose was about 14 times the Protoflow amount. The trial used 400 IU a day, about 180 mg, of a synthetic form of vitamin E (Klein et al., JAMA 2011 (SELECT)).
Protoflow lists 13 mg of vitamin E as D-alpha tocopheryl succinate, which is 87% of the Daily Value. In the natural form, 1 mg equals 1.49 IU, so 13 mg is about 19 IU (NIH ODS, Vitamin E). The adult upper limit is 1,000 mg a day.
A smaller dose is not proof of safety. SELECT did not test small doses, so it cannot show that 13 mg is harmless or that it carries risk. We report the gap and no more.
Who should ask a doctor about vitamin E?
Men with a history of prostate cancer, a high PSA, or a family history of it should ask a doctor before taking any vitamin E supplement. So should anyone on blood thinners. Large doses of vitamin E may raise bleeding risk with warfarin or antiplatelet drugs (NIH ODS, Vitamin E).
The men in SELECT were 50 or older with a PSA of 4.0 ng/mL or less, so the findings fit the age group that buys prostate formulas. Weak stream, straining or waking at night to pee need a doctor's check, because the cause matters: BPH, infection, diabetes or prostate cancer.
Unable to pee, blood in the urine, fever with painful peeing, or severe lower belly pain need urgent care.
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See packsHow can you keep vitamin E low in a supplement routine?
Add up vitamin E from every product you take, then compare the total with what your doctor advises. Multivitamins, skin-health pills and heart-health pills often carry it.
Keep taking prescribed medicine. Tell your doctor or pharmacist about each supplement, including Protoflow, and read the cautions on the side effects page.
- Read the vitamin E line on each label, in mg or IU
- Do not stack vitamin E products with Protoflow
- Ask your doctor before long-term use
The vitamin E and niacin lines are explained on our ingredient page. For the wider picture, see the prostate supplements guide.
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FAQ
Vitamin E and SELECT questions
01Who took part in the SELECT trial?
SELECT enrolled about 35,500 men: age 55 or older, or 50 or older for Black men, with a PSA of 4.0 ng/mL or less. They took selenium, vitamin E, both or placebo for several years.
02Did selenium change prostate cancer risk in SELECT?
Not significantly. Selenium alone showed a hazard ratio of 1.09, and selenium plus vitamin E showed 1.05, neither clearly different from placebo. Only the vitamin E group showed a significant rise, at 1.17.
03Should men take vitamin E to protect the prostate?
No. SELECT tested that idea and found more prostate cancers on vitamin E, not fewer. Nothing in the trial supports taking vitamin E to protect the prostate. Ask your doctor about prostate checks instead.
Who wrote this
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Pages built from the Protoflow label, the sales page and linked NIH, FDA, FTC, NHS and peer-reviewed sources.
Last updated . Learn about our editorial standards and how we check reviews. This website is run by Goprotoflow, a licensed U.S. retail desk for Protoflow, not by the manufacturer or by PhytoThrive Labs. We earn money when you buy through our order links.
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