The effect of calcium, vitamin D, or combined supplementation on fractures and falls in adults were assessed in this systematic review and meta-analysis. Randomised clinical trials were eligible, if they compared calcium, vitamin D, or combined supplementation with placebo or no treatment in adults (≥18 years) not receiving drug treatment for osteoporosis. The primary outcome was the risk of any fracture. Secondary outcomes included the risk of hip fracture, non-vertebral fracture, vertebral fracture, and falling, as well as the total number of falls. Pairs of reviewers independently screened trials, extracted data, and assessed risk of bias using the second version of Cochrane’s risk of bias tool. Findings were synthesised using random effects meta-analyses and appraised using Grading of Recommendations Assessment, Development and Evaluation, with application of thresholds for absolute effects considered important.
The review included 69 trials involving 153 902 participants. Participants in most of the trials were community dwelling (87%) and not at high risk of fractures or falls (73%). For the primary outcome of any fracture, little to no effect was found from use of calcium supplements (11 trials, 9067 participants; risk ratio 0.91, 95% confidence interval 0.81 to 1.01; moderate certainty), vitamin D supplements (36 trials, 92 045 participants; 1.00, 0.95 to 1.06; high certainty), or combined supplementation (15 trials, 51 126 participants; 0.91, 0.84 to 0.99; high certainty). Calcium, vitamin D, or combined supplementation appeared to have little to no effect on other fracture and fall outcomes, based largely on moderate to high certainty of evidence. The findings remained robust after an extensive exploration of heterogeneity across multiple subgroup analyses. Evidence for high risk patients or those requiring residential care was limited for many outcomes for calcium monotherapy and for combined supplementation.
The authors concluded that, based on absolute risk reductions and thresholds considered clinically meaningful, this review found little to no benefits from use of calcium, vitamin D, or combined supplementation on the prevention of fractures and falls.
An accompanying BMJ editorial points out that observational studies have associated low dietary calcium and low serum levels of vitamin D with low bone density and falls. Consequently, calcium, vitamin D, or combined supplementation has been widely promoted for preventive musculoskeletal health in older adults…
Th editorial concludes that other interventions, such as balance and resistance exercise, and several multicomponent interventions (eg, combining exercise, hazard assessment, or education with other interventions tailored to risk assessment) have been shown to offer meaningful prevention of falls and falls related injuries.
This new systematic review is a prime example for the slaying of a beautiful hypothesis with an ugly fact. But all is not negative – think of the money that can now be saved and put to better use!
This surely doesn’t mean that supplementation should not be undertaken in those with deficiencies or that such supplementation not be expected to reduce the risk of fractures in this subgroup.