title: Relationship between Vitamin D and Childhood Asthma: A Case-Control Study.
abstract: OBJECTIVE
  Studies determining the relationship between serum vitamin D status and childhood asthma have yielded controversial results. Findings indicated that vitamin D deficiency is associated with asthma and airway hyper responsiveness. The aim of this study was to assess the relationship between serum vitamin D status and childhood asthma.
  
  
  METHODS
  Data were obtained from 200 asthmatic children (age 3-12 years) and 200 healthy controls. Serum levels of 25(OH) vitamin D, total IgE, calcium, phosphorus, parathormone (PTH) and eosinophil count were measured in both asthmatic children and healthy controls. Also, the mean values of 25(OH) vitamin D were compared with asthma symptom severities.
  
  
  RESULTS
  There was a significant decrease in the concentration of serum 25(OH) vitamin D in the asthmatic patients as compared with the controls (20.34±2.8 vs 25.39±4.1 ng/mL, 95%CI: 1.46-3.86, P=0.01). Out of total asthmatic subjects, 40 (20%) were vitamin D sufficient, 48 (24%) were insufficient, and 112 (56%) were deficient. Total IgE concentration was also significantly higher in asthmatic patients having vitamin D deficiency (132.4±20.1 IU/ml, 95%CI: 1.38-3.75, P=0.03). Comparing asthmatic patients with healthy controls, odds of having vitamin D level less than 20ng/mL was 2.47.
  
  
  CONCLUSIONS
  Our findings suggest that vitamin D deficiency or insufficiency may be positively related to the prevalence of asthma in children.
authors.affiliation: Department of Pediatrics, Faculty of Medicine.
authors.forename: Gissou
authors.initials: G
authors.lastname: Hatami
authors.affiliation: Department of Pediatrics, Faculty of Medicine.
authors.forename: Khadijeh
authors.initials: K
authors.lastname: Ghasemi
authors.affiliation: Department of Community Medicine, Faculty of Medicine, ; The Persian Gulf Nuclear Medicine Research Center.
authors.forename: Niloofar
authors.initials: N
authors.lastname: Motamed
authors.affiliation: Department of Pediatrics, Faculty of Medicine.
authors.forename: Saiideh
authors.initials: S
authors.lastname: Firoozbakht
authors.affiliation: Department of Biochemistry.
authors.forename: Ali
authors.initials: A
authors.lastname: Movahed
authors.affiliation: The Persian Gulf Nuclear Medicine Research Center, ; Department of Immunology, Asthma and Allergy, The Persian Gulf Tropical Medicine Research Center, Bushehr University of Medical Sciences, Bushehr, Iran.
authors.forename: Shokrollah
authors.initials: S
authors.lastname: Farrokhi
keywords: Asthma; Children; Total IgE; Vitamin D status