Taking a vitamin D supplement every day could reduce your risk of certain cancers.
According to numerous research papers, taking three to four high strength (12.5 micrograms) tablets of vitamin D a day can reduce your risk of developing certain cancers by up to a quarter. Having enough vitamin D in your body is likely to reduce your risk of bowel, pancreatic, breast, prostate, ovarian, bladder, oesophageal, lung, kidney and uterine cancer as well as non-Hodgkins lymphoma and multiple myeloma.
Many of the studies looked at the link between vitamin D and specific cancers, such as prostate cancer, although some looked at any type of cancer. During the studies, people's vitamin D blood levels, vitamin D intake in food and supplements, and sun exposure was tracked. The researchers monitored the people in the studies and recorded the type and number of cancers that were diagnosed.
Although researchers are not exactly sure how vitamin D helps, some think it interacts with a number of genes in the body. If not enough vitamin D is present, the cells in the body are not able to go through their usual life-cycle. However, the exact reasons for the link between vitamin D and the decreased risk of developing certain cancers is not known at the moment.
Vitamin D is a simple and effective way to reduce your risk of developing certain cancers.
Dr Virginia Warren, assistant medical director, Bupa
Vitamin D can be found in oily fish, such as salmon, sardines or mackerel, and in fortified breakfast cereals. It is also produced naturally by your skin when it is exposed to sunlight. For most people, sunlight is their main source of vitamin D. Because of this, it's particularly important to ensure you are getting enough vitamin D during the winter months when the sun is weaker.
Dr Virginia Warren, assistant medical director for Bupa, commented: "There has been a lot of research over the last few years about the health benefits of taking a vitamin D supplement. Based on this evidence, we would recommend taking between 37.5 and 50 micrograms (1,500 - 2000 international units) of vitamin D on a daily basis to help reduce your risk of certain cancers. Spending time outside in summer will also increase your vitamin D levels, but is a risk for skin cancer.
"Ensuring you get enough vitamin D is a simple and effective way to reduce your risk of developing certain cancers. Alongside this, it's important to ensure you eat a healthy balanced diet, exercise regularly, only drink in moderation and do not smoke."
Read the studies
Hypponen E & Power C. Hypovitaminosis D in British adults at age 45 y: nationwide cohort study of dietary and lifestyle predictors. Am J Clin Nut 2007; 85:860-8 http://www.ajcn.org/cgi/content/abstract/85/3/860
Giovannucci E, Liu Y, Rimm E et al. Prospective study of predictors of vitamin D status and cancer incidence and mortality in men. Journal of the National Cancer Institute (JCNI) 2006; 98:451-59 doi: 10.1093/jnci/djj101
Oh K, Willett WC, Wu K, et al. Calcium and vitamin D intakes in relation to risk of distal colorectal adenoma in women. Am J Epidemiol. 2007; 165(10):1178-86. doi: 10.1093/aje/kwm026
Skinner HG, Michaud DS, Giovannucci E, et al. Vitamin D intake and the risk for pancreatic cancer in two cohort studies. Cancer Epidemiology Biomarkers & Prevention 2006; 15(9):1688-95. doi: 10.1158/1055-9965.epi-06-0206
John E, Dreon D, Koo J, et al. Residential sunlight exposure is associated with a decreased risk of prostate cancer. J Steroid Biochem Mol Biol 2004; 89-90:549-52. doi: 10.1016/j.jsbmb.2004.03.067
Lappe JM, Travers-Gustafson D, Davies KM, et al. Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial. Am J Clin Nutr 2007; 85(6):1586-91. http://www.ajcn.org/cgi/content/abstract/85/6/1586