Vitamin D and Regulatory T Cells

Abstract

Epidemiological studies highlight the rising prevalence of vitamin D deficiency and insufficiency and its association with poor respiratory health, including asthmatic disease. These and further studies have increased interest in the immunomodulatory properties of vitamin D beyond its well-de fi ned role in bone health and calcium homeostasis. The vitamin D receptor (VDR) is ubiquitously expressed in cells of the immune system including activated T cells. This chapter discusses recent evidence that vitamin D promotes a speci fi c T cell subset, namely regulatory T cells, which have a potentially vital role in the regulation of inappropriate disease-causing immune responses in the lung. Emerging clinical data on the capacity of vitamin D to promote both IL-10- and FoxP3-expressing cells are also discussed.