title: Vitamin D effects on lung immunity and respiratory diseases.
abstract: Our understanding of vitamin D metabolism and biological effects has grown exponentially in recent years and it has become clear that vitamin D has extensive immunomodulatory effects. The active vitamin D generating enzyme, 1α-hydroxylase, is expressed by the airway epithelium, alveolar macrophages, dendritic cells, and lymphocytes indicating that active vitamin D can be produced locally within the lungs. Vitamin D generated in tissues is responsible for many of the immunomodulatory actions of vitamin D. The effects of vitamin D within the lungs include increased secretion of the antimicrobial peptide cathelicidin, decreased chemokine production, inhibition of dendritic cell activation, and alteration of T-cell activation. These cellular effects are important for host responses against infection and the development of allergic lung diseases like asthma. Epidemiological studies do suggest that vitamin D deficiency predisposes to viral respiratory tract infections and mycobacterial infections and that vitamin D may play a role in the development and treatment of asthma. Randomized, placebo-controlled trials are lacking but ongoing.
authors.affiliation: Department of Medicine, University of Iowa Carver College of Medicine and Veterans Administration Medical Center, Iowa City, Iowa, USA.
authors.forename: Sif
authors.initials: S
authors.lastname: Hansdottir
authors.forename: Martha M
authors.initials: MM
authors.lastname: Monick
mesh_terms: D000818:Animals; D002117:Calcitriol / Q000378:metabolism; D006801:Humans; D007109:Immunity; D008168:Lung / Q000276:immunology* / Q000378:metabolism; D012140:Respiratory Tract Diseases / Q000209:etiology / Q000276:immunology* / Q000378:metabolism; D014807:Vitamin D / Q000502:physiology*; D014808:Vitamin D Deficiency / Q000503:physiopathology
chemical_list: D014807:Vitamin D; D002117:Calcitriol