title: Children with lower respiratory tract infections and serum 25-hydroxyvitamin D3levels: A case-control study.
abstract: Pneumonia is the leading cause of death in children under age of 5 years worldwide. The role of vitamin D in respiratory infections including pneumonia is unclear; therefore, we aimed to determine if children with lower respiratory tract infections had low serum 25-hydroxyvitamin D3.
  
  
  
  We performed a case-control study of children ages 3-60 months from the Guatemala City metropolitan area, hospitalized with community-acquired pneumonia between September and December 2012. Controls were selected from the well-baby/care immunization clinics serving the population from which cases emerged. We analyzed serum 25-hydroxyvitamin D3levels and conducted parental interviews to assess subject age, sex, race, feeding type, vitamin D supplementation, frequency of sun exposure, and maternal education. Height and weight were ascertained from medical records. Complete information was available for 70 (83%) of 84 eligible cases and 68 (60%) of 113 eligible controls.
  
  
  
  The median (IQR) serum 25-hydroxyvitamin D3concentration for cases was 23.2 ng/ml (14.4-29.9) compared to 27.5 ng/ml (21.4-32.3) in controls (P = 0.006). Multiple regression analysis using an a priori cut-point for vitamin D of <20 ng/ml showed that children with lower respiratory tract infections were more likely to have low 25-hydroxyvitamin D3levels than controls (adjusted odds ratio 2.4, 95% confidence interval 1.1-5.2, P = 0.02).
  
  
  
  Children with lower respiratory tract infections in Guatemala had low 25-hydroxyvitamin D3levels. Pediatr Pulmonol. 2016;51:1080-1087. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania. velarde13@gmail.com.|Department of Infectious Diseases, Hospital Roosevelt, Guatemala City. velarde13@gmail.com.
authors.forename: Angel Alfonso
authors.initials: AA
authors.lastname: Velarde López
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania.|Divisions of Infectious Diseases and Nephrology, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Gerber
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania.|Divisions of Infectious Diseases and Nephrology, Department of Pediatrics, The Children's Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania.|Department of Pediatrics, Divisions of Nephrology, Stanford University, California.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Leonard
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Dawei
authors.initials: D
authors.lastname: Xie
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Rita
authors.initials: R
authors.lastname: Schinnar
authors.affiliation: Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, Pennsylvania.|Biomedical and Health Sciences, Rutgers University, Newark, New Jersey.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Strom
mesh_terms: D002112:Calcifediol / Q000097:blood*; D016022:Case-Control Studies; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D006166:Guatemala / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D012141:Respiratory Tract Infections / Q000097:blood / Q000453:epidemiology*; D014808:Vitamin D Deficiency / Q000097:blood / Q000453:epidemiology*
chemical_list: D002112:Calcifediol
keywords: 25-hydroxyvitamin D3; Guatemala; case-control study; children; lower respiratory tract infections