Mounting evidence indicates that vitamin D and the vitamin D receptor (VDR) play unique roles in the pathogenesis of human diseases.In particular, we noted a consistent link between vitamin D/VDR signaling and intestinal inflammation.In addition to VDRs anti-inflammatory activity, our previous research shows that VDRs regulate anti-bacterial function in intestinal infection.The microbiome community is, along with the immune system, a critical factor in the development of chronic digestive diseases.We hypothesize that the intestinal VDRs alter the diversity and biological activity of the microbiome, thus regulating host defenses and inflammatory responses in healthy state, and failing to do so in chronic inflanmatory states, such as inflammatory bowel diseases and colon cancer..