Vitamin D2 supplements appear to reduce the risk of falls among women with a history of falling and low blood vitamin D levels living in sunny climates, especially during the winter, according to a report in the January 14 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.
"Approximately one-third of women older than 65 years fall each year, and 6 percent sustain a fracture as a result of the fall," the authors write as background information in the article. "In addition, fear of falling is a major problem in older people."
Richard L. Prince, M.D., of the Sir Charles Gairdner Hospital, Nedlands, Australia, and colleagues conducted a year-long clinical trial of 302 women age 70 to 90 years living in Perth, Australia. Because vitamin D is produced in response to sun exposure and the study was completed in a sunny climate, the researchers selected women with blood vitamin D levels below the median for the area (24 nanograms per milliliter). All participants had a history of falling in the previous year and received 1,000 milligrams of calcium citrate per day. Half were then randomly assigned to take either 1,000 international units of vitamin D2 (ergocalciferol) and half took an identical placebo. Data on falls were collected from participants every six weeks.
Eighty women (53 percent) in the vitamin D2 group and 95 women (62.9 percent) in the control group fell at least once during the study period. After adjusting for height, which affected the risk of falling and was significantly different between the two groups, vitamin D2 therapy reduced the risk of having at least one fall by 19 percent. "When those who fell were grouped by the season of first fall or the number of falls they had, ergocalciferol treatment reduced the risk of having the first fall in winter and spring but not in summer and autumn, and reduced the risk of having one fall but not multiple falls," the authors write.
"It is interesting that the ergocalciferol therapy effect was confined to those who were to sustain one fall but not those destined to have more than one fall," the authors write. "Older people who fall frequently tend to have more risk factors for falling, including greater degrees of disability and poorer levels of physical function." It is possible that chemically correcting vitamin D levels in the blood is insufficient to prevent falls in these individuals, they note. "Ergocalciferol, 1,000 international units per day, added to a high calcium intake is associated with 23 percent reduction of the risk of falling in winter/spring to the same level as in summer/autumn," the authors conclude.
(Arch Intern Med. 2008;168:103-108. Available pre-embargo to the media at www.jamamedia.org.)
Editor's Note: This study was supported by a research grant from the National Health and Medical Research Council of Australia. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.