VDR and inflammatory bowel disease: Binding to the vitamin D receptor (VDR) modulates immune responses by downregulating pro-inflammatory T helper (Th) cells, mainly suppressing Th1/Th17 pathways, and thereby reducing the secretion of cytokines, such as interferon-γ (INF-γ), interleukin 2 (IL-2), IL-17, and IL-23, which drive mucosal inflammation in IBD [10].