title: Vitamin D supplementation in children with asthma: a systematic review and meta-analysis.
abstract: BACKGROUND
  Epidemiologic studies suggest an association between vitamin D deficiency and atopic diseases, including asthma. The objective of this study was to systematically review the benefits and harms of vitamin D supplementation in children with asthma.
  
  
  METHODS
  We used standard Cochrane systematic review methodology. The search strategy included an electronic search in February 2013 of MEDLINE and EMBASE. Two reviewers completed in duplicate and independently study selection, data abstraction, and assessment of risk of bias. We pooled the results of trials using a random-effects model. We assessed the quality of evidence by outcome using the GRADE methodology.
  
  
  RESULTS
  Four trials with a total of 149 children met eligibility criteria. The trials had major methodological limitations. Given the four studies reporting on asthma symptoms used different instruments to measure that outcome, we opted not to conduct a meta-analysis. Three of those studies reported improvement in asthma symptoms in the vitamin D supplemented group study, while the fourth reported no effect (very low quality evidence). For the lung function outcome, a meta-analysis of two trials assessing post treatment FEV-1 found a mean difference of 0.54 liters per second (95% CI -5.28; 4.19; low quality evidence). For the vitamin D level outcome, a meta-analysis of three trials found a mean difference of 6.56 ng/ml (95% CI -0.64; 13.77; very low quality evidence).
  
  
  CONCLUSIONS
  The available very low to low quality evidence does not confirm or rule out beneficial effects of vitamin D supplementation in children with asthma. Large-scale, well-designed and executed randomized controlled trials are needed to better understand the effectiveness and safety of vitamin D in children with asthma.
authors: Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon. fares.munes@gmail.com.
authors: Munes M
authors: MM
authors: Fares
authors: Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon. lina.alkhaled@hotmail.com.
authors: Lina H
authors: LH
authors: Alkhaled
authors: Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon. smroueh@aub.edu.lb.
authors: Salman M
authors: SM
authors: Mroueh
authors: Department of Internal Medicine, American University of Beirut, Beirut, Lebanon. ea32@aub.edu.lb.|Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada. ea32@aub.edu.lb.|Department of Medicine, State University of New York at Buffalo, Buffalo, NY, USA. ea32@aub.edu.lb.
authors: Elie A
authors: EA
authors: Akl
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism / Q000503:physiopathology; D002648:Child; D002986:Clinical Trials as Topic; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D012129:Respiratory Function Tests; D014807:Vitamin D / Q000008:administration & dosage*; D014808:Vitamin D Deficiency / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism / Q000503:physiopathology
chemical_list: D014807:Vitamin D
references: Pediatr Pulmonol. 2003 Nov;36(5):399-404
references: 14520722
references: Mayo Clin Proc. 2013 Jul;88(7):720-55
references: 23790560
references: Dis Manag. 2004 Winter;7(4):305-13
references: 15671787
references: Ann N Y Acad Sci. 2004 Dec;1037:84-95
references: 15699498
references: N Engl J Med. 2006 Nov 23;355(21):2226-35
references: 17124020
references: J Allergy Clin Immunol. 2006 Dec;118(6):1299-304
references: 17157660
references: Am J Clin Nutr. 2007 Jan;85(1):6-18
references: 17209171
references: Pediatr Allergy Immunol. 2008 Mar;19(2):110-24
references: 17651373
references: Pediatrics. 2008 Aug;122(2):398-417
references: 18676559
references: Clin Exp Allergy. 2009 Dec;39(12):1830-41
references: 19817753
references: J Pediatr. 2010 Jun;156(6):948-52
references: 20236657
references: Immunol Allergy Clin North Am. 2010 Aug;30(3):397-409
references: 20670821
references: J Clin Epidemiol. 2011 Apr;64(4):383-94
references: 21195583
references: J Allergy Clin Immunol. 2011 Mar;127(3):724-33.e1-30
references: 21185068
references: J Allergy Clin Immunol. 2011 May;127(5):1294-6
references: 21315433
references: J Allergy Clin Immunol. 2011 May;127(5):1195-202
references: 21329969
references: Allergol Immunopathol (Madr). 2011 May-Jun;39(3):174-82
references: 21601133
references: Am J Respir Crit Care Med. 2011 Dec 15;184(12):1342-9
references: 21908411
references: Ann Allergy Asthma Immunol. 2012 Apr;108(4):281-2
references: 22469451
references: J Allergy Clin Immunol. 2004 Jan;113(1):59-65
references: 14713908