Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
, 351, h4580

Calcium Intake and Risk of Fracture: Systematic Review

Affiliations
Review

Calcium Intake and Risk of Fracture: Systematic Review

Mark J Bolland et al. BMJ.

Abstract

Objective: To examine the evidence underpinning recommendations to increase calcium intake through dietary sources or calcium supplements to prevent fractures.

Design: Systematic review of randomised controlled trials and observational studies of calcium intake with fracture as an endpoint. Results from trials were pooled with random effects meta-analyses.

Data sources: Ovid Medline, Embase, PubMed, and references from relevant systematic reviews. Initial searches undertaken in July 2013 and updated in September 2014.

Eligibility criteria for selecting studies: Randomised controlled trials or cohort studies of dietary calcium, milk or dairy intake, or calcium supplements (with or without vitamin D) with fracture as an outcome and participants aged >50.

Results: There were only two eligible randomised controlled trials of dietary sources of calcium (n=262), but 50 reports from 44 cohort studies of relations between dietary calcium (n=37), milk (n=14), or dairy intake (n=8) and fracture outcomes. For dietary calcium, most studies reported no association between calcium intake and fracture (14/22 for total, 17/21 for hip, 7/8 for vertebral, and 5/7 for forearm fracture). For milk (25/28) and dairy intake (11/13), most studies also reported no associations. In 26 randomised controlled trials, calcium supplements reduced the risk of total fracture (20 studies, n=58,573; relative risk 0.89, 95% confidence interval 0.81 to 0.96) and vertebral fracture (12 studies, n=48,967. 0.86, 0.74 to 1.00) but not hip (13 studies, n=56,648; 0.95, 0.76 to 1.18) or forearm fracture (eight studies, n=51,775; 0.96, 0.85 to 1.09). Funnel plot inspection and Egger's regression suggested bias toward calcium supplements in the published data. In randomised controlled trials at lowest risk of bias (four studies, n=44,505), there was no effect on risk of fracture at any site. Results were similar for trials of calcium monotherapy and co-administered calcium and vitamin D. Only one trial in frail elderly women in residential care with low dietary calcium intake and vitamin D concentrations showed significant reductions in risk of fracture.

Conclusions: Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures. Evidence that calcium supplements prevent fractures is weak and inconsistent.

Conflict of interest statement

Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf and declare: the study was funded by the Health Research Council (HRC) of New Zealand. MJB is the recipient of a Sir Charles Hercus Health Research Fellowship; IRR has received research grants and/or honorariums from Merck, Amgen, Lilly, and Novartis; all other authors have no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; no other relationships or activities that could appear to have influenced the submitted work.

Figures

None
Fig 1 Random effects models of effect of calcium supplements on risk of total fracture. Trials with no events are not included in meta-analyses
None
Fig 2 Random effects models of effect of calcium supplements on risk of hip fracture. Trials with no events are not included in meta-analyses
None
Fig 3 Random effects models of effect of calcium supplements on risk of vertebral fracture. Trials with no events are not included in meta-analyses
None
Fig 4 Random effects models of effect of calcium supplements on risk of forearm hip fracture. Trials with no events are not included in meta-analyses

Comment in

Similar articles

See all similar articles

Cited by 49 PubMed Central articles

See all "Cited by" articles

References

    1. IOM (Institute of Medicine). Dietary reference intakes for calcium and vitamin D. National Academies Press, 2011.
    1. Bailey RL, Dodd KW, Goldman JA, et al. Estimation of total usual calcium and vitamin D intakes in the United States. J Nutr 2010;140:817-22. - PMC - PubMed
    1. Anderson JJ, Roggenkamp KJ, Suchindran CM. Calcium intakes and femoral and lumbar bone density of elderly U.S. men and women: National Health and Nutrition Examination Survey 2005-2006 analysis. J Clin Endocrinol Metab 2012;97:4531-9. - PubMed
    1. Castro-Lionard K, Dargent-Molina P, Fermanian C, Gonthier R, Cassou B. Use of calcium supplements, vitamin D supplements and specific osteoporosis drugs among French women aged 75-85 years: patterns of use and associated factors. Drugs Aging 2013;30:1029-38. - PubMed
    1. Xiao Q, Murphy RA, Houston DK, Harris TB, Chow WH, Park Y. Dietary and supplemental calcium intake and cardiovascular disease mortality: the National Institutes of Health-AARP diet and health study. JAMA Intern Med 2013;173:639-46. - PMC - PubMed

Substances

Feedback