Calcium not sufficient for secondary osteoporosis prevention

Studies Cast Doubt on Use of Calcium in Some Cases

Poorly titled, this article describes an important finding.

Despite what doctors have long recommended, regularly taking calcium and vitamin D does not prevent fractures in older people who have broken a bone or who have osteoporosis, according to two large studies released yesterday.

People with osteoporosis are often encouraged to consume as much calcium and vitamin D as possible to strengthen their bones and to lower the likelihood of injuries.

But the new studies, involving thousands of elderly people in Britain who had symptoms of the disease, found that those who took calcium and vitamin D tablets were just as likely to break a bone as those who took neither.

The authors of the reports, published in The Lancet and the British medical journal BMJ, said their findings suggested that for people with brittle bones, relying solely on the supplements might not be enough.

“Our trial indicates that routine supplementation with calcium and vitamin D3, either alone or in combination, is not effective in the prevention of further fractures in people who have had a recent low-trauma fracture,” the authors of the Lancet study wrote.

Other experts called the findings important but cautioned that they did not apply to most people.

This study suggests to me that primary prevention of osteoporosis may have significant differences from secondary prevention of osteoporosis. To refresh memories, primary prevention activities attempt to prevent a disease occuring initially. Once a disease becomes symptomatic (heart attack, stroke, diabetes mellitus, osteoporotic fracture) then we consider secondary prevention. Secondary preventive measures seek to ameliorate and slow progression of the disease.

This study only speaks towards secondary prevention, or what to do for patients who already have fractures. Epidemiologic data still suggest that adequate dairy (calcium) intake helps in primary prevention.

Bottom line: after an osteoporotic fracture we should aggressively treat patients with interventions that decrease future fractures.