title: Limited evidence for calcium supplementation in preeclampsia prevention: a meta-analysis and systematic review.
abstract: OBJECTIVE
  This article synthesises evidence for calcium supplementation in preeclampsia prevention.
  
  
  METHODS
  Major databases and trial registries were searched, and comparisons were made against other meta-analyses.
  
  
  RESULTS
  Calcium supplementation reduced the overall risk of preeclampsia in 10 trials (n = 24 787; risk ratio (RR) 0.62; 95% confidence interval [CI] 0.47-0.81). Its effect was larger in two subgroups: low-baseline calcium intake (RR 0.42 [0.23-0.76]) and increased risk of developing hypertensive disorders (RR 0.36 [0.10-0.98]). This effect was not significant amongst larger studies (RR 0.93 [0.83-1.04]). Funnel plotting suggested possible publication bias.
  
  
  CONCLUSIONS
  Some evidence for calcium supplementation exists, but its utility is limited by the possibility of publication bias and a lack of large trials.
authors.affiliation: Department of Maternal-Fetal medicine, Royal Hospital for Women , Sydney , Australia .
authors.forename: Reuben
authors.initials: R
authors.lastname: Tang
authors.forename: Ing Ching
authors.initials: IC
authors.lastname: Tang
authors.forename: Amanda
authors.initials: A
authors.lastname: Henry
authors.forename: Alec
authors.initials: A
authors.lastname: Welsh
mesh_terms: D000328:Adult; D002118:Calcium / Q000008:administration & dosage*; D016001:Confidence Intervals; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D016017:Odds Ratio; D011225:Pre-Eclampsia / Q000517:prevention & control*; D011247:Pregnancy; D012306:Risk
chemical_list: D002118:Calcium
keywords: Calcium; Calcium supplementation; Meta-analysis; Preeclampsia; Systematic review