Calcium supplements have always been prescribed to women who are in postmenopausal stages to preserve bone health and some studies said it might also protect heart health by improving the ratio of good cholesterol to bad cholesterol.
However, according to the study by a research group at the University of Aukland, the opposite may be true, however UK experts warned women not to stop taking medication without medical advice.
Researchers have evaluated the women's calcium intake from diet and examined them every six months for five years, looking for reports of heart attack, stroke, or sudden death.
The researchers took two groups, one group taking the supplement, while the other group took a placebo.
The women who took the 1000 calcium supplement received and average of 861 milligrams of calcium from diet per day, boosting their total daily intake to 1,861.
The placebo group averaged 853 milligrams of calcium daily from their diet.
At least 31 out of 36 who took calcium suffered heart attack compared to 21 women on placebo having 22 heart attacks during their follow up period.
Study shows that the risk of a heart attack was about 1.5 times greater for those in the supplement group, but the link did not reach statistical significance.
