Calcium supplements 'double risk of heart attack', study finds [View all]
http://www.guardian.co.uk/society/2012/may/24/calcium-supplements-heart-risk

The new study challenges traditional wisdom on the benefits of calcium supplements. Photograph: Anthony Devlin/PA
Calcium supplements can almost double the risk of a heart attack, according to new research, and should be "taken with caution" and only for medical reasons, such as to prevent bone thinning. The study contradicts the commonly held belief that consuming extra calcium can help prevent heart disease or a stroke.
The findings are based on a study of the calcium intake of 23,980 men and women in Heidelberg, Germany, who were aged 35-64 when they joined a local cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) study in 1994-98. Researchers checked participants' health for 11 years afterwards, during which time 354 of them had a heart attack and 260 a stroke and there were 267 associated deaths. They also tracked how much calcium they consumed from any source.
They found that people who used calcium supplements regularly were 86% more likely to suffer a heart attack than those who did not.
This constituted "a statistically significantly increased myocardial infarction [heart attack] risk in comparison with non-users of any supplements", say the four co-authors led by Professor Sabine Rohrmann, from Zurich University's institute of social and preventative medicine.