There were 2.5 million breast cancer survivors in the United States in 2010, with an estimated 207,090 new cases diagnosed that year, according to the American Cancer Society. At the same time, a March 2009 report in the "Archives of Internal Medicine" indicated that three-quarters of U.S. adults have low levels of vitamin D, which is important because a deficiency increases the risk for the development of breast cancer. Vitamin D holds promise not only for preventing breast cancer but also for treating it and improving survival rates.
Identification
Vitamin D is found naturally in dairy products, fish and oysters; some foods are also fortified with it. Of the five forms of vitamin D, vitamins D-2 and D-3 are the most important for your health. Ongoing research shows vitamin D may play a role in preventing some cancers. A study in 2009 by the Cancer Treatment Centers of America found vitamin D deficiency was widespread in cancer patients regardless of nutritional status.
Vitamin D for Cancer Patients
Dr. JoEllen Welsh, of the State University of New York at Albany, started studying vitamin D in the 1980s. As part of her research, she treated human breast cancer cells in vitro with a potent form of vitamin D, and half the cancer cells died within a few days. The effects were even greater when vitamin D was injected into mice, shrinking tumors by more than 50 percent, with some tumors disappearing completely. A study published in "The Journal of Biological Chemistry" in January 2009 showed that the active form of vitamin D induces a tumor-suppressing protein. Although these results haven't been duplicated in human trials, researcher Sylvia Christakos, Ph.D., noted that the studies "provide a basis for the design of new anticancer agents that can target the protein as a candidate for breast cancer treatment," according to ScienceDaily.
Vitamin D for Cancer Prevention
A meta-review of the link between levels of vitamin D in blood and breast cancer risk was conducted in Germany and published in August 2010 in the "European Journal of Cancer." Overall, the studies included in the review all found a correlation between higher vitamin D intake, either from supplements or sun exposure, and a reduced risk for breast cancer. Research published in "The Breast Journal" in May 2008 mapped breast cancer rates worldwide and found a clear association between deficiency in exposure to sunlight, specifically ultraviolet B rays, and breast cancer.
Considerations
Vitamin D toxicity due to high intake can cause nausea, vomiting, poor appetite, constipation, weakness and weight loss. It can also raise calcium levels in the blood, leading to mental confusion, kidney stones or heart rhythm abnormalities. Very high doses can cause damage to the heart, blood vessels and kidneys. Check with your doctor before adding vitamin D supplements to your diet.
References
- Harvard School of Public Health; Vitamin D and Chronic Disease; Dr. Edward Giovannucci
- ScienceDaily; Vitamin D Found To Stimulate A Protein That Inhibits the Growth of Breast Cancer Cells; February 2009
- "Archives of Internal Medicine"; Demographic Differences and Trends of Vitamin D Insufficiency in the US Population, 1988-2004; A. Ginde, M.D., et al.; March 2009
- ABCNews.com; In Tests, Vitamin D Shrinks Breast Cancer Cells; Suzan Clarke; February 2010
- "European Journal of Cancer"; Meta-Analysis: Serum Vitamin D and Breast Cancer Risk; Y. Lin, et al.; August 2010
- "Journal of Biological Chemistry"; CCAAT Enhancer-binding Protein α Is a Molecular Target of 1,25-Dihydroxyvitamin D3 in MCF-7 Breast Cancer Cells; Puneet Dhawan, et al.; January 2009
