A study published on bmj.com today reports that a daily supplement of vitamin D at a dose of 700-1000 IU reduces by 19 percent the risk of falling among older people. However, a dose inferior to 700 IU per day has no effect.

IU is an international unit of measurement for vitamins and other biologically active substances.

One in three people aged 65 and older experience at least one fall, each year. Among those, around 6 percent result in a fracture. With the older segment of the population growing old, fall prevention has become a public health goal.

Earlier research indicates that vitamin D improves strength and balance among older people. However, other trials have found no noteworthy effect on the risk of falling.

In order to find out more, an international team of researchers evaluated the results of eight fall prevention trials. They assessed the effectiveness of vitamin D in preventing falls among older individuals, aged 65 or more. To minimize bias, differences in study design and feature were considered.

The collective results indicated that benefit from supplemental vitamin D on fall prevention depended on treatment dose.

Supplemental vitamin D2 and Vitamin D3 were investigated. 700-1000 IU supplemental vitamin D per day (vitamin D2 or vitamin D3) reduced falls by 19 percent and up to 26 percent with vitamin D3.

This outcome was independent of age, type of dwelling or additional calcium supplementation. The effect was considerable within two to five months of starting treatment. It extended beyond twelve months.

At a dose of less than 700 IU per day, supplemental vitamin D did not reduce falls.

Findings showed that the use of active forms of vitamin D did not appear to be more effective than 700-1000 IU supplemental vitamin D. In addition, active forms of vitamin D cost more than standard supplemental vitamin D. They are also associated with a higher risk for hypercalcaemia which is an elevated calcium level in the blood.

The authors say: “to reduce the risk of falling, a daily intake of at least 700-1000 IU supplemental vitamin D is warranted in all individuals aged 65 and older.”

In closing, they suggest that future research should explore the effectiveness of higher doses to optimize the fall prevention benefit with vitamin D.

“Fall prevention with supplemental and active forms of vitamin D: a meta-analysis of randomised controlled trials”
H A Bischoff-Ferrari, director of centre on aging and mobility, B Dawson-Hughes, director of bone metabolism laboratory, HB Staehelin, professor emeritus , J E Orav, associate professor of biostatistics, A EStuck, professor of geriatrics, R Theiler, head of rheumatology, J B Wong, professor of medicine , A Egli, fellow, D P Kiel, associate professor of medicine, J Henschkowski, fellow
BMJ 2009; 339:b3692
doi:10.1136/bmj.b3692
bmj.com

Written by Stephanie Brunner (B.A.)