Study: Vitamin D Supplements Have Little Effect on Risk of Falls in Older People

24 Apr 2014 --- A new study has discovered there is no evidence to suggest vitamin D supplements prevent falls, and that ongoing trials to test this theory are unlikely to change this result. The findings, published in The Lancet Diabetes & Endocrinology Journal, show that regularly taking Vitamin D supplements does not appear to reduce the risk of an elderly person having a fall.

The study, by Dr Mark Bolland of the University of Auckland, New Zealand, analysed findings from 20 randomized controlled trials which tested the potential of vitamin D supplements to reduce falls, in a total of 29,535 people. The study was conducted because Vitamin D supplementation is often recommended to prevent falls, primarily because it is considered to be important for maintaining and improving musculoskeletal health. The team wanted to assess whether there was a need for further research in this area.

Bolland told Nutrition Insight that Osteomalacia (in adults) and Rickets (in children) are caused by very low vitamin D levels, and are characterised by weak bones and fractures, and muscle pain and weakness.

“Treating these conditions with vitamin D supplements treats these problems,” he explained. “I think the idea the vitamin D supplements might be useful for musculoskeletal health probably arose from the suggestion that if very low vitamin D levels cause bone and muscle weakness, mildly low vitamin D levels might cause similar problems but to a lesser degree.

“This idea was reinforced by observational studies that showed that people with lower vitamin D levels have higher rates of falls and fractures than people with higher levels,” he explained. But Bolland also noted though that “people with lower vitamin D levels tend to be older, frailer and have other illnesses.”

Evidence from the current trials shows that raising vitamin D levels through the use of vitamin D supplements does not prevent falls. “This suggests that low vitamin D levels are a marker of frailty and high risk of falls rather than a cause of falls,” he said.

Strategies to reduce fall risk are urgently needed as the global population ages, as falls can be devastating to older people. The results of trials that have investigated the ability of vitamin D to prevent falls—and those of previous meta-analyses—have been mixed. It is unclear how vitamin D supplements might prevent falls but, until now, there has been enough positive evidence to support its recommendation by some health organizations.

Bolland and colleagues’ findings add to those of previous meta-analyses by also applying trial sequential analysis, which predicts the potential of future trials with a similar design to sway existing evidence. Their results suggest that trials in progress are unlikely to overturn the finding that vitamin D supplements do not appreciably reduce falls, and they conclude that there is insufficient evidence to support prescribing vitamin D to reduce falls.

Vitamin D supplements prevent osteomalacia in people with very low vitamin D levels who usually have clinical risk factors such as frailty, sunshine avoidance or deeply pigmented skin. Therefore, routinely treating adults at risk of osteomalacia (and children at risk of rickets) is still recommended, Bolland confirmed.

“However, other recent analyses have suggested no benefit of vitamin D supplements on a wide range of conditions (including preventing fractures, cardiovascular events, or cancer, or increasing bone density) in people who do not live in residential care,” he said. “When these results are taken together with the current results for vitamin D and falls, it suggests that healthy, active people are likely to receive enough sunshine to have adequate vitamin D levels and don’t need to take vitamin D supplements.”

According to Clifford Rosen of Maine Medical Research Institute, Scarborough, USA, and Christine Taylor of the National Institutes of Health, Bethesda, USA, both authors of a Comment linked to the study, “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.”

Full bibliographic information: "Vitamin D supplementation and falls: a trial sequential meta-analysis" Mark J Bolland, Andrew Grey, Greg D Gamble, Ian R Reid

by Sonya Hook