title: Do we need to take calcium with vitamin D supplements to prevent falls, fractures, and death?
abstract: OBJECTIVE
  The 2011 report by the US Institute of Medicine (IOM) on dietary reference intakes for calcium and vitamin D is based on meta-analyses of randomized controlled trials (RCTs), which concluded that vitamin D supplements need to be taken with calcium supplements to prevent falls, fractures, and all-cause mortality. This study reviews recent meta-analyses of RCTs of vitamin D supplementation to determine whether their conclusions are consistent with the meta-analyses underpinning the IOM report.
  
  
  RESULTS
  Since 2007 when the first IOM meta-analysis was published, up to May 2012, there have been nine meta-analyses of RCTs of vitamin D supplements on risk of falls, 10 on fractures, and five on all-cause mortality. About half of these reported summary effects for both vitamin D combined with calcium supplements and also vitamin D alone. However, statistical testing of results from recent meta-analyses does not support the conclusions of the IOM meta-analyses.
  
  
  CONCLUSIONS
  The inconsistency in the conclusions from meta-analyses is due to limitations in the design of previous RCTs of vitamin D supplementation. Large RCTs, giving higher doses of vitamin D (without calcium), should provide a clear answer within several years as to whether vitamin D supplements are beneficial by themselves.
authors.affiliation: School of Population Health, University of Auckland, Auckland, New Zealand. r.scragg@auckland.ac.nz
authors.forename: Robert
authors.initials: R
authors.lastname: Scragg
mesh_terms: D000058:Accidental Falls / Q000517:prevention & control; D002136:Calcium, Dietary / Q000008:administration & dosage*; D019587:Dietary Supplements; D050723:Fractures, Bone / Q000517:prevention & control*; D006801:Humans; D015201:Meta-Analysis as Topic; D009026:Mortality; D016032:Randomized Controlled Trials as Topic; D014807:Vitamin D / Q000008:administration & dosage*
chemical_list: D002136:Calcium, Dietary; D014807:Vitamin D