AUCKLAND, New Zealand, Sept. 30 (UPI) -- Calcium supplements have long been recommended to older people as a method of increasing bone density and preventing bone fracture, however two studies have shown they have little to no effect on either.
Guidelines for older men and women suggest an intake of 1000 to 1200 mg of calcium per day, and many take supplements to meet the recommendations.
"Collectively, these results suggest that Clinicians, advocacy organisations and health policymakers should not recommend increasing calcium intake for fracture prevention, either by use of calcium supplements or dietary sources," said Dr. Mark Bolland, an associate professor of medicine at the University of Auckland, in a press release. "For most patients who are concerned about their bone health, they do not need to worry about their calcium intake."
The first study, published in the British Medical Journal, looked at whether dietary or supplemental calcium helped to increase bone density in people over age 50.
Researchers analyzed 59 controlled trials; 15 focused on dietary calcium in 1,533 participants and 51 studied the effect of supplements in 12,257 participants. The studies found that calcium acquired through diet or supplement increased bone density by between 0.6 and 2 percent over the course of two years -- which researchers conclude is unlikely to lead to a significant reduction in risk for bone fractures.
In the second study, also published in the British Medical Journal, researchers looked at 50 reports based on 44 cohort studies on the effects of dietary, milk and dairy intake. They found that most showed no relation between any form of dietary intake of calcium and incidence of fracture.
The same study also included a review of 26 studies with around 50,000 participants taking calcium supplements, finding they also had little effect on the risk for bone fracture.
Professor Karl Michaëlsson of Uppsala University writes in an editorial, also published in the British Medical Journal, that both studies call calcium intake guidelines for older people into question, and that they should be re-evaluated not only for their usefulness, but the potential health risk they may pose.
"Most will not benefit from increasing their intakes and will be exposed instead to a higher risk of adverse events such as constipation, cardiovascular events, kidney stones, or admission for acute gastrointestinal symptoms," Michaëlsson wrote. "The weight of evidence against such mass medication of older people is now compelling, and it is surely time to reconsider these controversial recommendations."