title: Vitamin D modulation of innate immune responses to respiratory viral infections.
abstract: Vitamin D, in addition to its classical functions in bone homeostasis, has a modulatory and regulatory role in multiple processes, including host defense, inflammation, immunity, and epithelial repair. Patients with respiratory disease are frequently deficient in vitamin D, implying that supplementation might provide significant benefit to these patients. Respiratory viral infections are common and are the main trigger of acute exacerbations and hospitalization in children and adults with asthma and other airways diseases. Respiratory monocytes/macrophages and epithelial cells constitutively express the vitamin D receptor. Vitamin D, acting through this receptor, may be important in protection against respiratory infections. Whether the in vitro findings can be translated into a substantial in vivo benefit still remains uncertain. Here we review the in vitro data on the role of vitamin D in antiviral innate immunity, the data concerning the deficient levels of vitamin D in lung diseases, and the in vivo role of supplementation as protection against respiratory viral infections in healthy individuals and in patients with chronic respiratory diseases. Finally, we suggest ways of improving the effectiveness of vitamin D as an adjuvant in the prevention and treatment of acute respiratory infections.
authors.affiliation: Department of Hematology, Iuliu Hatieganu University of Medicine and Pharmacy Cluj and Ion Chiricuta Oncology Institute, Cluj-Napoca, Romania.
authors.forename: Mihnea T
authors.initials: MT
authors.lastname: Zdrenghea
authors.affiliation: Airways Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK.
authors.forename: Heidi
authors.initials: H
authors.lastname: Makrinioti
authors.affiliation: Department of Hematology, Iuliu Hatieganu University of Medicine and Pharmacy Cluj and Ion Chiricuta Oncology Institute, Cluj-Napoca, Romania.|Laboratory of Immunology and Immunotherapy, University Hospital Brest, France.
authors.forename: Cristina
authors.initials: C
authors.lastname: Bagacean
authors.affiliation: Department of Paediatric Respiratory Medicine, Royal Brompton Hospital and Imperial College London, London, UK.
authors.forename: Andy
authors.initials: A
authors.lastname: Bush
authors.affiliation: Airways Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK.
authors.forename: Sebastian L
authors.initials: SL
authors.lastname: Johnston
authors.affiliation: Department of Hematology, Iuliu Hatieganu University of Medicine and Pharmacy Cluj and Ion Chiricuta Oncology Institute, Cluj-Napoca, Romania.|Airways Disease Infection Section, National Heart and Lung Institute, Imperial College London, London, UK.
authors.forename: Luminita A
authors.initials: LA
authors.lastname: Stanciu
mesh_terms: D006801:Humans; D007113:Immunity, Innate; D007155:Immunologic Factors / Q000378:metabolism; D012141:Respiratory Tract Infections / Q000276:immunology*; D014777:Virus Diseases / Q000276:immunology*; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D007155:Immunologic Factors; D014807:Vitamin D
keywords: innate immunity; respiratory viruses; vitamin D