Scientists study risk factors and protective factors to find ways to prevent new cancers from starting. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.
Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Risk factors that a...
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:
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:
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.
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This information is produced and provided by the National
Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National
Institute via the Internet web site at http://
.gov or call 1-800-4-CANCER.
WebMD Public Information from the National Cancer Institute
September 04, 2014
This information is not intended to replace the advice of a doctor.
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