title: Effects of daily iron supplementation in primary-school-aged children: systematic review and meta-analysis of randomized controlled trials.
abstract: BACKGROUND
  Anemia is an important public health and clinical problem. Observational studies have linked iron deficiency and anemia in children with many poor outcomes, including impaired cognitive development; however, iron supplementation, a widely used preventive and therapeutic strategy, is associated with adverse effects. Primary-school-aged children are at a critical stage in intellectual development, and optimization of their cognitive performance could have long-lasting individual and population benefits. In this study, we summarize the evidence for the benefits and safety of daily iron supplementation in primary-school-aged children.
  
  
  METHODS
  We searched electronic databases (including MEDLINE and Embase) and other sources (July 2013) for randomized and quasi-randomized controlled trials involving daily iron supplementation in children aged 5-12 years. We combined the data using random effects meta-analysis.
  
  
  RESULTS
  We identified 16 501 studies; of these, we evaluated 76 full-text papers and included 32 studies including 7089 children. Of the included studies, 31 were conducted in low- or middle-income settings. Iron supplementation improved global cognitive scores (standardized mean difference 0.50, 95% confidence interval [CI] 0.11 to 0.90, p = 0.01), intelligence quotient among anemic children (mean difference 4.55, 95% CI 0.16 to 8.94, p = 0.04) and measures of attention and concentration. Iron supplementation also improved age-adjusted height among all children and age-adjusted weight among anemic children. Iron supplementation reduced the risk of anemia by 50% and the risk of iron deficiency by 79%. Adherence in the trial settings was generally high. Safety data were limited.
  
  
  CONCLUSIONS
  Our analysis suggests that iron supplementation safely improves hematologic and nonhematologic outcomes among primary-school-aged children in low- or middle-income settings and is well-tolerated.
authors.forename: Michael
authors.initials: M
authors.lastname: Low
authors.forename: Ann
authors.initials: A
authors.lastname: Farrell
authors.forename: Beverley-Ann
authors.initials: BA
authors.lastname: Biggs
authors.forename: Sant-Rayn
authors.initials: SR
authors.lastname: Pasricha
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000188:drug therapy*; D002648:Child; D002657:Child Development / Q000187:drug effects*; D019587:Dietary Supplements; D004334:Drug Administration Schedule; D006801:Humans; D007501:Iron / Q000008:administration & dosage*; D012574:Schools
chemical_list: D007501:Iron