Vitamin D may not protect against breast cancer, according to a new study from the journal Breast Cancer Research. Looking at data on 613 women with breast cancer and 1,218 women without the disease, researchers found no link between breast cancer risk and blood levels of vitamin D.
Past research on vitamin D and cancer has yielded mixed results. In laboratory tests on cancer cells, for instance, scientists have found that vitamin D may slow the spread of cancer and promote the death of cancer cells. At the same time, a number of clinical trials have shown 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).
Since maintaining optimal vitamin D levels is important to overall health--especially bone health--many medical experts recommend increasing your vitamin D intake. Although vitamin D is found in some foods and can be produced by the body during sun exposure, using supplements may be a more reliable means of boosting your vitamin D levels.