© 2014 Informa UK Ltd. The emerging role of vitamin D as a regulator of both innate and adaptive immune responses has encouraged the investigation of its role in the pathogenesis of a variety of autoimmune conditions including the inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. Animal models consistently demonstrate that vitamin D significantly impacts on the modulation of astrointestinal inflammation, while epidemiological and observational data show an inverse relationship between vitamin D status and the onset/progression of Crohn's disease as well as the development of colorectal cancer. As vitamin D supplementation is readily available, at low cost, it is a very attractive potential therapeutic option. The biological plausibility for a role for vitamin D in inflammation modulation, the potential genetic links associated with vitamin D metabolism and the clinical aspects for it in IBD will be discussed.