Heart warning over calcium supplements

A review of studies among 12,000 people taking the supplement found they had a 30 per cent increased risk of a heart attack. The supplements are often prescribed to older women for the prevention or treatment of osteoporosis.

According to the Food Standards Agency, adults need 700mg of calcium a day, from dietary sources including milk, cheese and green leafy vegetables, to help build strong bones and teeth.

Today's study, from experts at universities in Auckland and Aberdeen, said it was the effect of supplements, which increase the levels of calcium circulating in the blood, that causes the problems, prompting them to call for a rethink of the provision of supplements for bone health.

Experts believe higher blood serum levels lead to hardening of the arteries, which can cause heart attacks.

"Given the modest benefits of calcium supplements on bone density and fracture prevention, a reassessment of the role of calcium supplements in the management of osteoporosis is warranted," they said.

Prof John Cleland, a cardiologist at Castle Hill Hospital, Hull, in an accompanying commentary in the British Medical Journal, said supplements improved bone density but were ineffective in reducing fractures.

He said patients with osteoporosis should generally not be treated with them unless they were also receiving treatment for the condition.