Some research suggests that boosting your levels of vitamin D may help lower your cancer risk. Available in supplement form, vitamin D is an essential vitamin that plays a key role in immune function and helps reduce inflammation. While studies on vitamin D and cancer prevention have yielded mixed results, there's some evidence that people with higher levels of vitamin D may have a decreased risk for certain types of cancer.
The Science Behind Vitamin D and Cancer
To date, most of the scientific support for vitamin D's potential role in cancer prevention comes from observational studies (i.e., studies that examine specific characteristics of a particular population).
In a 2006 report, for instance, investigators reviewed 63 observational studies on vitamin D levels and risk of cancer (including colon cancer, breast cancer, and prostate cancer). According to the report, most of the studies showed that people with ample vitamin D levels had a lower cancer risk.
A number of clinical trials (i.e., studies that test the effects of a certain treatment or health intervention) have also focused on vitamin D and cancer risk. For example, a 2007 study of 1,179 healthy women (all of whom were over age 55) assigned each participant to one of three interventions: one group was given 1,400 to 1,500 mg of calcium daily; a second group was given calcium plus 1,110 IU of vitamin D; the third group was given a placebo. After four years, those who took both calcium and vitamin D showed a significantly reduced risk for all types of cancer (compared to those who took calcium only or the placebo).
On the other hand, a number of other clinical trials have found that taking vitamin D supplements failed to reduce risk of breast cancer and colorectal cancer (two of the most common forms of cancer in the United States).
Should You Take Vitamin D Supplements for Cancer Prevention?
Given the lack of supporting research, it's too soon to tell whether taking vitamin D supplements can reduce cancer risk. To that end, the National Cancer Institute does not recommend for or against the use of vitamin D supplements to reduce the risk of any type of cancer.
However, since maintaining optimal vitamin D levels is important to overall health, many medical experts recommend increasing your vitamin D intake. Although vitamin D is found in some foods (such as oily fish and fortified milk) and can be produced by the body during sun exposure, taking supplements may be a more reliable means of upping your vitamin D levels.
If you're interested in using vitamin D supplements to boost your cancer defense (or for any other health purpose), talk to your doctor about finding a supplement that's right for you.
American Cancer Society. "Vitamin D". Last accessed October 2010.
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