More study needed on calcium and heart attacks
This article first appeared in the St. Louis Beacon, May 6, 2011 - The phones in Dr. Kathryn Diemer's office began ringing when patients heard about a new study claiming that calcium supplements can cause health problems.
Diemer, an osteoporosis expert and assistant professor of medicine at Washington University, tried to allay concerns voiced at the other end of the line by offering a combination of medical advice and common sense. First, consuming about 1,000 to 1,200 mg of calcium can be useful in preventing osteoporosis, she says. But she adds that some women need exercise caution.
The study, reported in the British Medical Journal, showed "modest increases" in risks of "cardiovascular events, especially myocardial infarction" and stroke among women taking calcium supplements. Because of the findings, the study concluded that "a reassessment of the role of calcium supplements in osteoporosis management is warranted."
Diemer says some of her callers were "absolutely" surprised by the findings. "We hear that calcium is such a good thing," she said. "We already know that vitamin D lowers heart disease, and we tell everybody to take calcium and vitamin D as part of the treatment regimen. That's how we treat osteoporosis now."
About 22 million women have osteoporosis, she says.
"What patients can do, post-menopausal women certainly should do, is have a bone density study done and talk to their doctor about how much calcium they're taking, and how much they should take," Diemer said. "Vitamin D should be part of (the discussion), too."
She says even patients who think they are consuming only 1,200 mg of calcium a day need to step back and ask themselves how much of the mineral they actually might be getting in their diet.
"A lot of patients come in and say that since 1,200 mg is good, wouldn't 2,400 be better? I don't think that's true. There may be a risk in very high doses by women with heart disease. If they're having a glass of milk a day, that's about 300 mg, and if they have yogurt or cheese, that's another 300. We should be cautious about overtreating. Patients may be getting enough in their diet, which is probably the best way to do it."
She says the study has touched off "an interesting discussion. But everyone is saying we need more information." In the meantime, she says post-menopausal women and men over 70 should educate themselves on osteoporosis prevention.
"It's not just a woman's problem. It can be a man's, too," Dr. Diemer said. "Understand that this is an important disease."
Funding for the Beacon's health reporting is provided in part by the Missouri Foundation for Health, a philanthropic organization that aims to improve the health of the people in the communities it serves.