title: Vitamin D deficiency associated with increased incidence of gastrointestinal and ear infections in school-age children.
abstract: BACKGROUND
  Vitamin D deficiency (VDD) is highly prevalent among children worldwide. The effects of VDD include alterations of the immune response and increased risk of infection but little evidence exists in school-age children. We investigated the association of vitamin D status with morbidity in a prospective study of school-age children from Bogotá, Colombia.
  
  
  METHODS
  We measured plasma 25-hydroxyvitamin D (25(OH)D) concentrations in a random sample of 475 children (mean ± standard deviation age: 8.9 ± 1.6 years) and followed them for an academic year. Caregivers were asked to record daily information on the incidence of morbidity episodes using pictorial diaries. Baseline vitamin D status was classified according to 25(OH)D concentrations as deficient (<50 nmol/L), insufficient (≥50 and <75 nmol/L) or sufficient (≥75 nmol/L). We used Poisson regression to estimate incidence rate ratios and 95% confidence intervals for days with diarrhea, vomiting, diarrhea with vomiting, cough with fever and earache or discharge with fever, comparing vitamin D-deficient with vitamin D-sufficient children. Estimates were adjusted for child's age, sex and household socioeconomic status.
  
  
  RESULTS
  The prevalence of VDD was 10%; an additional 47% of children were vitamin D-insufficient. VDD was associated with increased rates of diarrhea with vomiting (adjusted incidence rate ratio: 2.05; 95% confidence interval: 1.19, 3.53) and earache/discharge with fever (adjusted incidence rate ratio: 2.36; 95% confidence interval: 1.26, 4.44). VDD was not significantly related to cough with fever.
  
  
  CONCLUSIONS
  These results suggest that VDD is related to increased incidence of gastrointestinal and ear infections in school-age children. The effect of correcting VDD on reducing risk of these infections needs to be tested in supplementation trials.
authors: Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA. kthornton@epi.msu.edu
authors: Kathryn A
authors: KA
authors: Thornton
authors: Constanza
authors: C
authors: Marín
authors: Mercedes
authors: M
authors: Mora-Plazas
authors: Eduardo
authors: E
authors: Villamor
mesh_terms: D002648:Child; D003105:Colombia / Q000453:epidemiology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D010031:Otitis / Q000453:epidemiology*; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications*
chemical_list: D014807:Vitamin D; C104450:25-hydroxyvitamin D