Vitamin D may help prevent falls in older women

NEW YORK (Reuters Health) - Vitamin D2 supplements plus calcium may lower the risk of falls among older women who have a high risk of falling, according to a year-long clinical study conducted in Perth, Australia.

Elderly women who are at risk of falling can benefit from extra vitamin D and calcium to reduce their risk by 63 percent to 53 percent a year - "a drop of about 20 percent," Dr. Richard L. Prince, of University of Western Australia, Perth, and the Sir Charles Gairdner Hospital, Nedlands, told Reuters Health.

"In addition, they can expect that this treatment will reduce their fracture risk by about 20 percent over five years...a big health benefit for a small change in diet," he added.

Roughly one third of women older than 65 years fall each year, with 6 percent sustaining a fracture, Prince and associates note in a report published Monday in the Archives of Internal Medicine.

They studied the impact of vitamin D2 supplementation in 302 women ages 70 to 90 years who had a history of falling. Both groups received 1,000 milligrams calcium citrate daily.

Because exposure to the sun boosts vitamin D levels and this study was conducted in sunny Perth, the researchers selected women with blood vitamin D levels below average for the area, they explain. Half of the women took 1,000 international units of vitamin D2 (ergocalciferol) daily and half took a matching placebo.

Over the course of 12 months, 80 women (53 percent) in the vitamin D2 group fell at least once compared with 95 women (63 percent) in the control group. After taking into account height, which affected the risk of falling and was significantly different between the two groups, vitamin D2 supplementation lowered the risk of at least one fall by 19 percent, the report indicates.

When the researchers grouped the women who fell by season of first fall or the number of falls suffered, they found that vitamin D2 supplementation reduced the risk of having the first fall in winter and spring but not in summer and autumn. Vitamin D2 at a dose of 1,000 IU per day plus calcium was associated with a "23 percent reduction of the risk of falling in winter/spring to the same level as in summer/autumn," Prince and colleagues report.

It is "interesting," they add, that vitamin D2 reduced the risk of experiencing one fall but not multiple falls. They suggest this may be because older people who fall frequently tend to have more risk factors for falling, including more disability and poorer physical function. It is possible, therefore, that correcting vitamin D deficiency through supplements is not enough to prevent falls in these individuals.

SOURCE: Archives of Internal Medicine, January 14, 2008.