Vitamin D supplements do not prevent falls
In their state of the art review on falls, Vieira and colleagues conclude that the strategy of supplementing calcium and vitamin D reduces the risk of falls.1 But their conclusion is based on contradictory evidence. They cite two meta-analyses from 2009 and 2010 of 7 and 9 trials respectively reporting that vitamin D reduced falls, but another from 2012 of 7 trials reporting no reduction in fall rates with vitamin D.
The analyses cited by Vieira and colleagues have been superseded. Meta-analyses now include 23 trials of >30,000 participants, and report no effect of vitamin D with or without calcium supplements on falls (RR 0.98, 95%CI 0.94-1.02, P=0.25).2 These results reliably exclude a clinically important 10% reduction in falls from vitamin D supplementation.3 Similar data show that vitamin D with or without calcium does not reduce total fractures by 10%,4 but co-administered calcium and vitamin D prevented hip fractures in 2 trials in frail elderly women living in residential care.5
Interpreting meta-analyses of vitamin D is fraught. There are more than 50 meta-analyses published on vitamin D with or without calcium and falls or fracture. Comparing these meta-analyses highlights important differences in trial selection, outcome definition, and analytic methods that lead to markedly different conclusions between the meta-analyses.6,7 The best available evidence from recent meta-analyses, that include data from all available trials analyzed in a standard intention-to-treat manner, is that vitamin D supplementation does not prevent falls.
1. Vieira ER, Palmer RC, Chaves PH. Prevention of falls in older people living in the community. BMJ 2016;353:i1419.
2. Bolland MJ, Grey A, Reid IR. Should we prescribe calcium or vitamin D supplements to treat or prevent osteoporosis? Climacteric 2015;18(sup2):22-31.
3. Bolland MJ, Grey A, Gamble GD, et al. Vitamin D supplementation and falls: a trial sequential meta-analysis. Lancet Diabetes Endocrinol 2014;2(7):573-80.
4. Bolland MJ, Grey A, Gamble GD, et al. The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis. Lancet Diabetes Endocrinol 2014;2(4):307-20.
5. Avenell A, Mak JC, O'Connell D. Vitamin D and vitamin D analogues for preventing fractures in post-menopausal women and older men. Cochrane database of systematic reviews (Online) 2014;4:CD000227.
6. Bolland MJ, Grey A. A case study of discordant overlapping meta-analyses: vitamin d supplements and fracture. PloS one 2014;9(12):e115934.
7. Bolland MJ, Grey A, Reid IR. Differences in overlapping meta-analyses of vitamin d supplements and falls. J Clin Endocrinol Metab 2014;99(11):4265-72.
Competing interests: We have published and analysed meta-analyses of vitamin D on falls and fractures.