SEATTLE — Calcium supplementation appears to reduce by 34% the 5-year risk of fracture in elderly women, according to a population-based study presented at the annual meeting of the American Society for Bone and Mineral Research.
The benefit was seen as early as 13 months, even though women were deemed at baseline to be getting adequate calcium—a mean of 960 mg/day, said Richard Prince, M.D., of Sir Charles Gairdner Hospital, Perth, Australia.
The 1,460 healthy ambulatory women, aged 70 or older, were randomly assigned to receive 600 mg calcium carbonate twice daily or placebo. Calcium intake was assessed and dual x-ray absorptiometry (DXA) scans were taken at baseline and again at least 1 year later. During the 5-year study, the rates of death, withdrawal, and treatment cessation were similar between the two groups. In all, 235 individuals sustained 296 fractures; 118 in those taking calcium and 178 in those taking placebo, for an overall 34% reduction in fractures in patients in the calcium group who stuck to the protocol for the entire study period.
Calcium appeared to improve bone mineral density at cortical bone sites, according to DXA findings. At 13 months, there were early indications of a reduction in fracture rates among patients in the calcium group.