Calcium supplements may increase the risk of a heart attack in older women, New Zealand research suggests.
The supplements are often prescribed to postmenopausal women to help counter loss of bone density. Previous research suggested they might also protect against vascular disease by cutting blood cholesterol levels.
However, the latest British Medical Journal study found the opposite to be true, although UK experts warned women not to stop taking medication.
The University of Auckland team followed 1,471 healthy postmenopausal women for five years.
Each woman either took a daily calcium supplement, or a dummy pill. Heart attacks were more common in the group who took the supplements.
After a careful analysis of the data, the researchers confirmed 36 heart attacks in 31 women who took the supplements, compared with 22 heart attacks in 21 women who took the placebo.
Rates of stroke and sudden death were also higher in the supplement group - although not conclusively.
Source - BBC