Research is needed to find treatments for osteoporosis with and without calcium and vitamin D supplements, Cleland said.
"Newer treatments and some old neglected ones, like thiazide diuretics, do reduce fractures and reduce mortality," he said. "We don't know whether or not you need to take calcium and vitamin D to make them work. We know supplements are a waste of time by themselves, but [whether they] act as adjuvants for effective therapy is not known."
Duffy MacKay, vice president for scientific and regulatory affairs at the Council for Responsible Nutrition, a supplement industry lobbying group, described the conclusion by Reid's group as weak because none of the studies used in the report were specifically designed to look at the risk for heart attack.
"I see a very strong conclusion, and I think that [it] is very overstated," he said. "My conclusion to this is [that] here is some preliminary evidence suggesting something we need to look at with additional clinical trials."
MacKay said he advises people to get 1,000 to 1,500 milligrams of calcium a day from dairy products and leafy green vegetables. If your diet doesn't contain enough calcium, then the gap can be filled with a calcium supplement, he said.
For people who take calcium supplements, MacKay advises not taking the dose all at once, but breaking it up over the day so that calcium levels in the blood don't increase beyond normal.
The U.S. Office of Dietary Supplements has more on calcium supplements.
SOURCES: Ian Reid, M.D., department of medicine, Faculty of Medical and Health Sciences, University of Auckland, New Zealand; John Cleland, M.D., departme
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