Vitamin D is obtained from limited dietary sources, and cutaneous conversion of 7-dehydrocholesterol by UVB radiation. Many studies, including those conducted in Canada, have revealed widespread vitamin D deficiency/ insufficiency. Epidemiological data provide clear correlations between vitamin D insufficiency and the prevalence of several cancers, particularly those of the digestive tract, consistent with chemopreventive effects of vitamin D. A meta-analysis of randomized controlled trials provided an association between vitamin D supplementation and human longevity. The active form of vitamin D interacts with the vitamin D receptor (VDR). We have found that the VDR regulates the function of a protein called sirtuin 1 (Sirt1). Sirt1 function is important for prevention of cancers of the digestive tract, in particular colon cancer, which is noteworthy given the evidence that vitamin D sufficiency contributes colon cancer chemoprevention. We are interested in understanding the functional consequences of the interaction of the VDR with Sirt 1, and its role in cancer chemoprevention by vitamin D.

This study is funded by the Environment-Cancer Fund^TM. Thank you to Read for the Cure for their financial contribution to this project.