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Cancer Prevention Overview (PDQ®): Prevention - Patient Information [NCI] - Interventions That Are Not Known to Lower Cancer Risk

Vitamin and dietary supplements have not been shown to prevent cancer.

An intervention is a treatment or action taken to prevent or treat disease, or improve health in other ways.

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Overview

This complementary and alternative medicine (CAM) information summary provides an overview of the use of PC-SPES as a treatment in people with cancer. The summary includes a brief history of PC-SPES research, the results of clinical trials, and possible adverse effects of PC-SPES. Included in this summary is a discussion of the contamination of PC-SPES and its withdrawal from avenues of distribution. This summary contains the following key information: PC-SPES is a patented mixture of eight...

Read the Overview article > >

There is not enough proof that taking multivitamin and mineral supplements or single vitamins or minerals can prevent cancer. The following vitamins and mineral supplements have been studied, but have not been shown to lower the risk of cancer:

  • Vitamin B6.
  • Vitamin B12.
  • Vitamin E.
  • Vitamin C.
  • Beta carotene.
  • Folic acid.
  • Selenium.
  • Vitamin D.

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) found that vitamin E taken alone increased the risk of prostate cancer. The risk continued even after the men stopped taking vitamin E. Taking selenium with vitamin E or taking selenium alone did not increase the risk of prostate cancer.

Vitamin D has also been studied to see if it has anticancer effects. Skin exposed to sunshine can make vitamin D. Vitamin D can also be consumed in the diet and in dietary supplements. Taking vitamin D in doses from 400-1100 IU / day has not been shown to lower the risk of cancer.

The VITamin D and OmegA-3 TriaL (VITAL) is under way to study whether taking vitamin D (2000 IU/ day) and omega-3 fatty acids from marine (oily fish) sources lowers the risk of cancer.

The Physicians' Health Study found that men who have had cancer in the past and take a multivitamin daily may have a slightly lower risk of having a second cancer.

See the following PDQ summaries for more information:

  • Breast Cancer Prevention
  • Colorectal Cancer Prevention
  • Lung Cancer Prevention
  • Prostate Cancer Prevention

New ways to prevent cancer are being studied in clinical trials.

Clinical trials are taking place in many parts of the country. Check NCI's list of cancer clinical trials for cancer prevention trials that are now accepting patients.

See the NCI Web site for more information about cancer prevention.

    This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http:// cancer .gov or call 1-800-4-CANCER.

    WebMD Public Information from the National Cancer Institute

    Last Updated: September 04, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
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