Calcium plus vitamin D supplementation and risk of fractures: an updated meta-analysis from the National Osteoporosis Foundation.
The aim was to meta-analyze randomized controlled trials of calcium plus vitamin D supplementation and fracture prevention. Meta-analysis showed a significant 15 % reduced risk of total fractures (summary relative risk estimate [SRRE], 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87).


BACKGROUND
Calcium plus vitamin D supplementation has been widely recommended to prevent osteoporosis and subsequent fractures; however, considerable controversy exists regarding the association of such supplementation and fracture risk. The aim was to conduct a meta-analysis of randomized controlled trials [RCTs] of calcium plus vitamin D supplementation and fracture prevention in adults.


METHODS
A PubMed literature search was conducted for the period from July 1, 2011 through July 31, 2015. RCTs reporting the effect of calcium plus vitamin D supplementation on fracture incidence were selected from English-language studies. Qualitative and quantitative information was extracted; random-effects meta-analyses were conducted to generate summary relative risk estimates (SRREs) for total and hip fractures. Statistical heterogeneity was assessed using Cochran's Q test and the I (2) statistic, and potential for publication bias was assessed.


RESULTS
Of the citations retrieved, eight studies including 30,970 participants met criteria for inclusion in the primary analysis, reporting 195 hip fractures and 2231 total fractures. Meta-analysis of all studies showed that calcium plus vitamin D supplementation produced a statistically significant 15 % reduced risk of total fractures (SRRE, 0.85; 95 % confidence interval [CI], 0.73-0.98) and a 30 % reduced risk of hip fractures (SRRE, 0.70; 95 % CI, 0.56-0.87). Numerous sensitivity and subgroup analyses produced similar summary associations. A limitation is that this study utilized data from subgroup analysis of the Women's Health Initiative.


CONCLUSIONS
This meta-analysis of RCTs supports the use of calcium plus vitamin D supplements as an intervention for fracture risk reduction in both community-dwelling and institutionalized middle-aged to older adults.
Department of Nutrition Science, Women's Global Health Institute, Purdue University, West Lafayette, IN, USA.
C M
CM
Weaver
EpidStat Institute, Evergreen, CO, USA.
D D
DD
Alexander
Cancer Epidemiology Program, University of Hawaii Cancer Center, Honolulu, HI, USA.
C J
CJ
Boushey
Jean Mayer USDA Human Nutrition Research Center on Aging, Bone Metabolism Laboratory, Tufts University, Boston, MA, USA.
B
B
Dawson-Hughes
School of Nursing, Creighton University, Omaha, NE, USA.|School of Medicine, Creighton University, Omaha, NE, USA.
J M
JM
Lappe
Skeletal Health and Osteoporosis Center and Bone Density Unit, Calcium and Bone Section, Division of Endocrinology, Diabetes, and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
M S
MS
LeBoff
Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy, Tufts University, Boston, MA, USA.
S
S
Liu
Division of Health and Nutrition Examination Statistics, National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville, MD, USA.
A C
AC
Looker
National Osteoporosis Foundation, 1150 17th Street NW, Suite 850, Washington, DC, 20036, USA. taylor.wallace@nof.org.|Department of Nutrition and Food Studies, George Mason University, Fairfax, VA, USA. taylor.wallace@nof.org.
T C
TC
Wallace
Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA.
D D
DD
Wang
D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D002118:Calcium / Q000627:therapeutic use*; D019587:Dietary Supplements; D004359:Drug Therapy, Combination; D006801:Humans; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000188:drug therapy; D058866:Osteoporotic Fractures / Q000209:etiology / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic; D018570:Risk Assessment / Q000379:methods; D014807:Vitamin D / Q000627:therapeutic use*
D050071:Bone Density Conservation Agents; D014807:Vitamin D; D002118:Calcium
Calcium; Fracture; Supplement; Vitamin D