Daily vitamin D supplements do not significantly reduce the risk for falls in the elderly, according to a meta-analysis of 20 randomized controlled trials published online April 23 in the Lancet Diabetes & Endocrinology.
The analysis suggests further trials on the subject would not change the result.
Mark J. Bolland, PhD, associate professor, Department of Medicine, University of Auckland, New Zealand, and colleagues analyzed randomized controlled trials testing the effect of vitamin D supplements on the risk for falls in 29,535 elderly people. The researchers used a risk reduction threshold of 15% and followed that with a sensitivity analysis applying a 10% risk reduction threshold.
Results in both analyses lay within the "futility boundary," the authors write, meaning it is improbable that further testing would provide favorable results.
Subgroup analyses showed no reduction in falls for the 6 trials that tested vitamin D with calcium, involving 9919 people, nor did they find benefit in the 16 trials testing vitamin D without calcium, involving 22,291 people.
"Future trials with similar designs are unlikely to alter these conclusions. At present, there is little justification for prescribing vitamin D supplements to prevent falls," the authors write.
The authors analyzed trials in which participants were given cholecalciferol or ergocalciferol, omitting trials of hydroxylated vitamin D or vitamin D analogues. They also omitted trials that included other interventions and trials with populations with chronic comorbidities other than osteoporosis or frailty. Seventeen of the trials were double-blind, placebo-controlled trials.
In an accompanying commentary, Clifford J. Rosen, MD, director of the Center for Clinical and Translational Research, Maine Medical Research Institute, Scarborough, and Christine L. Taylor, PhD, scientific consultant, Office of Dietary Supplements, National Institutes of Health, Bethesda, Maryland, discussed the conflicting conclusions reached in meta-analyses examining the effect of vitamin D supplements and fall risk.
They suggest that conflicting conclusions may arise from the relatively small number of trials compared with the number of meta-analyses. In fact, they report, there are twice as many meta-analyses on vitamin D and falls as there are trials. Further, some trials may have too few participants. They note that Dr. Bolland found that larger trials showed no effect of supplementation.
Further, the commentators note, the way some investigators measure vitamin efficacy in fall prevention, such as using gait speed, may not relate directly to falls. Finally, the way authors report data could "mask important details of the relation between intervention and outcome," they write. For instance, studies often report total number of falls without reporting whether the falls represent individuals who fell several times.
"The work of Bolland and colleagues contributes to the ongoing controversy concerning interventions to reduce falls in older people," the commentators write. "However, their futility analysis raises new and important questions about the likelihood of showing an effect of vitamin D supplementation on falls from small, underpowered, randomised trials. Whether a large trial is feasible in this vulnerable population remains to be established. Until then, we are left with uncertainty about the benefits of vitamin D supplementation for reduction in fall risk, particularly among vulnerable older people."
The authors and commentators have disclosed no relevant financial relationships.
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Cite this: Vitamin D No Help in Fall Risk, Large Meta-Analysis Shows - Medscape - Apr 24, 2014.