Taking calcium supplements or eating more dairy to improve bone health has little or no effect, according to new research.
There is scant evidence that taking calcium supplements prevents fractures and no evidence that increasing calcium through the diet prevents fractures or breaks either, experts said.
The research, published in the British Medical Journal (BMJ), collected data from dozens of studies on the issue.
According to the NHS, adults need 700mg of calcium a day. It is recommended that people get all the calcium they need from their daily diet.
The NHS Choices website warns that taking high doses of calcium (over 1,500mg a day) could lead to stomach pain and diarrhoea.
It says taking supplements containing less than this amount are unlikely to cause any harm.
In the latest study, experts from New Zealand concluded that efforts to increase calcium intake to improve bone health had no overall effect.
“Our analyses indicate that dietary calcium intake is not associated with risk of fracture, and there is no evidence currently that increasing dietary calcium intake prevents fractures,” they said.
They said calcium supplements have “an unfavourable risk:benefit profile”, meaning they could do more harm than good.
“Collectively, these results suggest that clinicians, advocacy organisations, and health policymakers should not recommend increasing calcium intake for fracture prevention, either with calcium supplements or through dietary sources.”
The experts studied a range of trials on the issue, including people aged 50 and over getting their calcium from milk or dairy, or taking calcium supplements with or without vitamin D.
In an accompanying editorial, Karl Michaelsson from Uppsala University in Sweden, said most over-50s will not benefit from increasing their intake of calcium, particularly through supplements, as some recommendations suggest.
“The weight of evidence against such mass medication of older people is now compelling, and it is surely time to reconsider these controversial recommendations,” he said.