Mucosal tissues and especially the intestine are constantly exposed to abundant non-self
materials yet simultaneously establish immune homeostasis to prevent excessive inflammatory
responses. The maintenance of intestinal homeostasis is achieved by a harmonized immune network
mediated by endogenous factors (e.g., cytokines and chemokines) and exogenous factors (e.g., commensal bacteria and
dietary matter). Specifically, vitamins from such exogenous sources function immunologically in the control of
homeostatic immune responses; thus, their deficient or excessive intake is associated with the development of
inflammatory diseases. The focus of this review is the immunologic functions of vitamins B3, B9, A, and D in the
regulation and development of inflammation.