Study suggests calcium supplements increase heart attack risk

Daily calcium supplements have been long recommended by doctors for their adult patients to help prevent osteoporosis, but a new study suggests the pills may put users at a slightly greater risk of heart attacks. The findings were recently published in the British Medical Journal, and have caused a ripple of concern among patients and physicians.

Most doctors recommend that their adult patients aged 50 and older get 1,200 milligrams of calcium from either diet or supplements, or a combination of both. People with osteoporosis are generally prescribed calcium supplements along with bone-building medications. The supplements have been shown to slightly reduce the risk of bone fractures.

But this new study, conducted by researchers from the University of Auckland in New Zealand, the University of Aberdeen in Scotland, and Darthmouth Medical School, raises questions about the benefits of daily calcium pills.

The study involved data from 11 clinical trials with about 12,000 adults, who were on average in their early 40s. Researchers found 166 cases of heart attack among those who took 500 milligrams or more of calcium a day compared to 130 cases in patients who took a placebo. Another study, which included five clinical trials involving more than 8,000 adults, showed heart attacks in 143 patients who took calcium supplements, compared with 111 patients who took a placebo. The overall risk from all the studies was about 30 percent.

Some bone doctors have disregarded the findings, arguing that the study did not look at the risks of calcium supplements when taken with vitamin D. The Women’s Health Initiative, was which was not included in the researchers’ study, showed no increased risk of heart attack in more than 36,000 female study participants ages 50 to 76 who were taking calcium with vitamin D.

Most doctors say the results are eye-opening, but patients shouldn’t throw out their calcium supplements just yet. They say more research is needed to determine the most beneficial dosage of calcium for all patients.