(Ivanhoe Newswire) -- Women age 70 years or older who received a single annual
high dose of vitamin D had a higher rate of falls and fractures than did women
who received placebo.
Kerrie M. Sanders, Ph.D., of the University of Melbourne, Geelong, Australia and
colleagues conducted a study to examine whether high-dose cholecalciferol
(vitamin D) given orally once a year to older women would reduce falls and
fractures. The vitamin D was given in a single, high-dose to address low
adherence. The trial included 2,256 community-dwelling women, ages 70 years or
older, considered to be at high risk of fracture. They were recruited from June
2003 to June 2005 and were randomly assigned to receive 500,000 IU of vitamin D
or placebo each year for 3 to 5 years. The study concluded in 2008.
The trial participants had a total of 5,404 falls over the study period, with 74
percent of women in the vitamin D group and 68 percent of women in the placebo
group having at least one fall. Analysis indicated women in the annual high-dose
vitamin D group experienced 15 percent more falls. Women in the vitamin D group
had 171 fractures vs. 135 in the placebo group, with 26 percent more fractures
for participants in the vitamin D group, who also had a 31 percent higher
incidence of falls in the first 3 months following dosing.
"This is the first study to demonstrate increased risk of falls associated with
any vitamin D intervention and the second study to demonstrate an increased
fracture risk associated with annual high-dose vitamin D therapy in elderly
women.
"This line of reasoning is supported by the temporal risk pattern that we
observed and the fact that harm has not been reported in the numerous studies
that have used more frequent dosing. Thus, it is reasonable to speculate that
high serum levels of vitamin D or metabolites resulting from the large annual
dose, subsequent decrease in the levels, or both might be causal."
SOURCE: Journal of the American Medical Association (JAMA), May 12, 2010
