title: Vitamin D status, aeroallergen sensitization, and allergic rhinitis: A systematic review and meta-analysis.
abstract: The role of vitamin D status in the etiology of allergic diseases is uncertain. The aim of this study was to investigate the association of vitamin D status with risk of two main outcomes: aeroallergen sensitization and allergic rhinitis (AR).
  
  
  
  We performed a systematic review of Medline, Scopus, Science Citation Index, and Google Scholar databases. Studies were included if they reported on prevalent or incident cases of aeroallergen sensitization or AR according to vitamin D status. Quality assessment, data extraction and meta-analysis were performed.
  
  
  
  A total of 21 observational studies were included. Children with serum 25(OH)D ≥75 nmol/L had significantly reduced odds of aeroallergen sensitization, but neither vitamin D intake in pregnancy nor vitamin D supplementation in infancy were associated with risk of AR. Individuals with serum 25(OH)D ≥75 nmol/L had lower prevalence of AR compared to those with serum 25(OH)D <50 nmol/L (OR; 0.71, 95%CI; (0.56-0.89), p = 0.04). This association was mainly observed in adult men; prevalence of AR was lower in men with serum 25(OH)D ≥75 nmol/L compared to men with serum 25(OH)D <50 nmol/L, while this association was not observed in women.
  
  
  
  The current literature suggests significant age- and sex-specific relations of vitamin D status to risk of aeroallergen sensitization and AR.
authors.affiliation: a Students' Scientific Research Center, Tehran University of Medical Sciences , Tehran , Iran.|b Department of Public Health , Tehran University of Medical Sciences , Tehran , Iran.|c Pediatric Respiratory Diseases Education and Research Network (PRDERN), Universal Scientific Education and Research Network (USERN) , Tehran , Iran.|d Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences , Tehran , Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Aryan
authors.affiliation: d Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences , Tehran , Iran.|e Network of Immunity in Infection, Malignancy and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN) , Tehran , Iran.|f Universal Scientific Education and Research Network (USERN) , Tehran , Iran.
authors.forename: Nima
authors.initials: N
authors.lastname: Rezaei
authors.affiliation: g Department of Emergency Medicine, and Division of Rheumatology, Allergy, and Immunology, Department of Medicine , Massachusetts General Hospital, Harvard Medical School , Boston , Massachusetts , USA.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Camargo
mesh_terms: D000328:Adult; D000367:Age Factors; D000393:Air Pollutants / Q000276:immunology; D000485:Allergens / Q000276:immunology; D002648:Child; D006801:Humans; D007114:Immunization; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D015995:Prevalence; D065631:Rhinitis, Allergic / Q000453:epidemiology*; D012306:Risk; D012737:Sex Factors; D014807:Vitamin D / Q000097:blood*
chemical_list: D000393:Air Pollutants; D000485:Allergens; D014807:Vitamin D
keywords: Aeroallergen; allergic rhinitis; atopy; diet; vitamin D