title: An update on vitamin D and human immunity.
abstract: In the last 5 years, there has been a remarkable change in our understanding of the health benefits of vitamin D. The classical actions of vitamin D as a determinant of mineral metabolism and rachitic bone disease have been expanded to include a broader role in skeletal homoeostasis and prevalent bone disorders such as osteoporosis. However, it is the nonskeletal function of vitamin D that has attracted most attention. Although pluripotent responses to vitamin D have been recognized for many years, our new perspective on nonclassical vitamin D function stems from two more recent concepts. The first is that impaired, vitamin D status is common to many populations across the globe. This has prompted studies to explore the health impact of suboptimal circulating levels of vitamin D, with association studies linking vitamin D 'insufficiency' to several chronic health problems including autoimmune and cardiovascular disease, hypertension and common cancers. In support of a broader role for vitamin D in human health, studies in vitro and using animal models have highlighted immunomodulatory and anticancer effects of vitamin D that appear to depend on localized activation of vitamin D. The conclusion from these reports is that many nonclassical actions of vitamin D are independent of conventional vitamin D endocrinology and are therefore more sensitive to variations in vitamin D status. The current review summarizes these developments, with specific reference to the newly identified effects of vitamin D on the immune system, but also highlights the challenges in translating these observations to clinical practice.
authors: Department of Orthopaedic Surgery and Molecular Biology Institute, David Geffen School of Medicine at UCLA, 615 Charles E. Young Drive South,Los Angeles, CA 90095, USA. mhewison@mednet.ucla.edu
authors: Martin
authors: M
authors: Hewison
mesh_terms: D056704:Adaptive Immunity / Q000187:drug effects* / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D019587:Dietary Supplements; D006801:Humans; D007113:Immunity, Innate / Q000187:drug effects* / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D018448:Models, Immunological; D018167:Receptors, Calcitriol / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D014807:Vitamin D / Q000008:administration & dosage* / Q000276:immunology / Q000378:metabolism
chemical_list: D018167:Receptors, Calcitriol; D014807:Vitamin D