Peer-review started: July 14, 2015
First decision: September 22, 2015
Revised: October 24, 2015
Accepted: November 23, 2015
Article in press: November 25, 2015
Published online: March 27, 2016
Effective adaptive immune responses rely upon appropriate activation of T cells by antigenic peptide-major histocompatibility complex on the surface of antigen presenting cells (APCs). Activation relies on additional signals including co-stimulatory molecules on the surface of the APCs that promote T cell expansion. The immune response is further sculpted by the cytokine environment. However, T cells also respond to other environmental signals including hormones, neurotransmitters, and vitamins. In this review, we summarize the mechanisms through which vitamins A and D impact immune responses, particularly in the context of T cell responses.
Core tip: Vitamins are organic compounds that are required in small quantities as nutrients. When used as dietary supplements, vitamins can be used to treat diseases and maintain physiological processes including bone and skin health. Vitamins also play important roles in immune system including lymphocyte activation, and T helper cell differentiation. Among all the vitamins, vitamin A and D have garnered more interest in clinical setting. In this review we have focused on how vitamin A and D regulate adaptive immunity especially how both the vitamins modulate T cell responses. We have highlighted the mechanisms how these vitamins affect T helper cell differentiation. How these vitamins affect inflammatory disorders including allergy and autoimmune diseases have also been described in this review. The purpose of this review is to suggest the potential of dietary supplements such as vitamin A and D can be used to treat inflammatory disorders.