I saw this news on the front page of British newspapers today and it is also on yahoo:

"
People taking calcium supplements may increase their risk of a heart attack by as much as 30 per cent, new research suggests.

Scientists from the universities of Auckland and Aberdeen analysed the results of 11 studies involving 12,000 people who took 500mg calcium supplements or more each day.

They found people taking the supplements had a 30 per cent increased risk of heart attack and smaller "non-significant" increases in the risk of stroke and death.

The findings were the same for men and women and were independent of age and type of supplement given.

Calcium supplements are often prescribed to older adults to help prevent or treat osteoporosis, but the researchers said the findings suggest this may need to be reconsidered.

Although taking supplements leads to a "modest increase" in heart attack risk, their widespread use means that even a small increase may translate into a large number of heart attacks within a population.

Supplements may cause raised levels of calcium in the blood which can lead to hardening of the arteries, say the researchers.

However, dietary calcium appears to have little effect on heart attack risk. The Food Standards Agency says adults require 700mg of calcium a day for healthy bones. Good dietary sources of calcium include milk, cheese and green, leafy vegetables.

Writing in today's online British Medical Journal, the researchers concluded: "Given the modest benefits of calcium supplements on bone density and fracture prevention, a reassessment of the role of calcium supplements in osteoporosis management is warranted."

Judy O’Sullivan, a senior cardiac nurse at the British Heart Foundation, said: “We need to be cautious about the results of this analysis because none of the studies involved were designed to look specifically at the relationship between calcium supplements and the risk of heart attack.

“However, the research should not be completely ignored. Any new guidelines on the prevention of fractures in those most vulnerable to them should take this type of analysis into account.

“Anyone who has been advised by their doctor to take calcium supplements shouldn't stop because of this research alone.” "