title: The relationship between serum vitamin D and chronic rhinosinusitis: A systematic review.
abstract: BACKGROUND
  An exciting development in upper respiratory tract disease is the pathophysiology of vitamin D (VD3). There now is substantial literature to indicate that VD3 acts as an immunomodulator of adaptive and innate immunity locally within the respiratory epithelium. Chronic rhinosinusitis (CRS) places a relatively large socioeconomic burden on developed nations, yet remains a difficult disease to treat. VD3, therefore, has become an area of clinical interest because it may provide an adjunctive drug therapy option in CRS, thereby potentially improving the quality of life of these patients.
  
  
  OBJECTIVE
  A systematic review of the relationship among serum VD3 levels, CRS phenotype, and disease severity by using outcome assessments.
  
  
  METHODS
  A systematic search was performed by using the PubMed, MEDLINE, and EMBASE databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Studies that measured serum VD3 levels and correlated the measurements to any subtype of CRS (with or without nasal polyps) were included for qualitative analysis.
  
  
  RESULTS
  Seven articles were included (four prospective and three retrospective studies), with a total of 539 patients. There were significantly lower VD3 levels in the polypoid phenotypes of CRS compared with controls. Low VD3 levels were often associated with an increased degree of inflammation.
  
  
  CONCLUSIONS
  The available evidence indicated that there is a significant relationship between low VD3 levels and polypoid CRS phenotypes. The association between VD3 levels and disease severity and VD3 potential for drug therapy remains unclear, which warrants further research in the area.
authors: Department of Surgery, South West Healthcare, Warrnambool, Australia.
authors: Patrick J
authors: PJ
authors: Stokes
authors: Joanne
authors: J
authors: Rimmer
mesh_terms: D000818:Animals; D001249:Asthma / Q000276:immunology*; D002908:Chronic Disease; D018450:Disease Progression; D006801:Humans; D012220:Rhinitis / Q000276:immunology*; D012852:Sinusitis / Q000276:immunology*; D014807:Vitamin D / Q000097:blood / Q000276:immunology*
chemical_list: D014807:Vitamin D