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Need for additional calcium to reduce the risk of hip fracture with vitamin d supplementation: evidence from a comparative metaanalysis of randomized controlled trials

S. Boonen, P. Lips, R. Bouillon, H. Bischoff-Ferrari, D. Vanderschueren, P. Haentjens

Journal of Clinical Endocrinology and Metabolism, 2007

45,509 participants · 575 citations

Abstract

PURPOSE: The purpose of this study was to extend the metaanalysis of Bischoff-Ferrari et al., which found that 700-800 IU/d vitamin D reduced hip fracture risk in elderly individuals by 25%, by defining the need for additional calcium supplementation in individuals receiving vitamin D for the prevention of hip fractures. DATA SOURCES: MEDLINE and EMBASE.com (search terms: "vitamin D" and "hip fracture"), bibliographies of articles retrieved, and the authors' reference files were used as data sources. STUDY SELECTION: Selected studies were randomized controlled trials (RCTs) of oral vitamin D with or without calcium supplementation vs. placebo/no treatment in postmenopausal women and/or older men (>or=50 yr) specifically reporting a risk of hip fracture. DATA EXTRACTION: Independent extraction was performed by two authors using predefined criteria, including study quality indicators. DATA SYNTHESIS: All pooled analyses are based on random-effects models. Based on four RCTs (9083 patients), the pooled relative risk (RR) of hip fracture for vitamin D alone was 1.10 [95% confidence intervals (CI) 0.89, 1.36]. No between-trial heterogeneity was observed. For the six RCTs (45,509 patients) of vitamin D with calcium supplementation, the pooled RR for hip fracture was 0.82 (95% CI 0.71, 0.94). There was no heterogeneity between trials. In an adjusted indirect comparison of the summary RRs from the two metaanalyses, the RR for hip fracture for vitamin D with calcium vs. vitamin D…

How strong is the evidence?

Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 45,509 participants or records.

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