Calcium and vitamin D supplements do not appear to reduce the risk of fractures among older, community-dwelling women, according to David J. Torgerson, Ph.D., of the University of York (England), and his colleagues.
Although supplementation with calcium and vitamin D are routinely recommended for fracture prevention in the elderly, this is the second study in recent weeks to call this practice into question.
A secondary prevention trial, also in the United Kingdom, failed to show any benefit of calcium or vitamin D, either alone or in combination, in preventing fractures (Lancet 2005;365:1621–8).
Dr. Torgerson's study randomly assigned 1,321 women to receive 1,000 mg calcium plus 800 IU cholecalciferol (vitamin D3) daily and a leaflet on calcium intake and prevention of falls, and 1,993 women were given the leaflet only.
The women were aged 70 years or older, and had one or more risk factors for hip fracture (BMJ 2005;330:1003).
Over an average follow-up of 25 months, there were 149 clinical fractures, which was lower than expected. But the difference in fracture rates between the supplemented and control groups was not significant (58 vs. 91).
In the supplemented group, the odds ratio was 1.01 for all fractures and 0.75 for hip fractures.
There was no evidence that vitamin D supplementation reduced the incidence of falls, as previously hypothesized.
A recent metaanalysis found a 22% reduction in falls with vitamin D supplementation (JAMA 2004;291:1999–2006).
Calcium and vitamin D supplements have been shown to reduce hip fractures among older women in French nursing homes.
“People living in sheltered accommodation or nursing homes may be at more risk of a low calcium and vitamin D intake and at higher risk of fracture,” the authors suggest.
Limitations of the study were that it lacked a placebo preparation, was underpowered, and had relatively wide confidence intervals, the authors noted.