Calcium supplements raise risk of heart damage

Taking calcium in the form of supplements may raise the risk of plaque buildup in arteries and heart damage, new research has found.

The finding should not, however, stop you from eating calcium-rich foods as the researchers added that such a diet may even be beneficial for the heart.

"Our study adds to the body of evidence that excess calcium in the form of supplements may harm the heart and vascular system," said Erin Michos, Associate Professor at Johns Hopkins University School of Medicine in in Baltimore, Maryland.

The findings, published in the Journal of the American Heart Association, are based on analysis of 10 years of medical tests on more than 2,700 people in a federally funded heart disease study in the US.

The participants chosen for this study ranged in age from 45 to 84, and 51 per cent were female. 

The researchers found that among participants with highest dietary intake of calcium -- over 1,022 milligrams per day -- there was no increase in relative risk of developing heart disease over the 10-year study period.

But supplement users showed a 22 per cent increased likelihood of having their coronary artery calcium scores rise higher than zero over the decade, indicating development of heart disease.

"There is clearly something different in how the body uses and responds to supplements versus intake through diet that makes it riskier," study co-author John Anderson, Professor Emeritus at University of North Carolina at Chapel Hill's Gillings School of Global Public Health, said.

"It could be that supplements contain calcium salts, or it could be from taking a large dose all at once that the body is unable to process," Anderson noted.

"Based on this evidence, we can tell our patients that there doesn't seem to be any harm in eating a heart-healthy diet that includes calcium-rich foods, and it may even be beneficial for the heart," Michos said. 

"But patients should really discuss any plan to take calcium supplements with their doctor to sort out a proper dosage or whether they even need them," Michos noted.