Vitamin D, Immunity and Human Disease

Abstract

There is now increasing evidence that a key feature of vitamin D physiology is its ability to act as modulator of innate and adaptive immunity. This article will review the effects of vitamin D on innate immune responses with specific emphasis on the autocrine induction of antibacterial responses in macrophages, and the regulation of dendritic cell-mediated antigen presentation. The impact of vitamin D on adaptive immunity will also be reviewed, focusing on the effects of vitamin D on T-cell function, particularly the induction of regulatory T-cells. The review will also explore the impact of vitamin D deficiency on these facets of immune function, as well as the possible benefits of vitamin D supplementation. Finally, the review will also include an appraisal of human diseases such as infection and autoimmune disease that may be substantially influenced by vitamin D-dependent regulation of human immunity.