Spilt milk

Excess dietary calcium goes into toilets, not bones.

- ANDREA GRAVES

Every year, about 4000 people in New Zealand fracture their hip. Judging from how my mother seemed last year when it happened to her, it is worth avoiding. The crumpled top of her femur, which was pronounced to consist of thin bone, was promptly replaced, and she received brochures advising her to drink and eat plenty of calcium - the big sources of which include dairy, sardines and vegetables such as squash and bok choy.

This advice is standard, but it does nothing to reduce the risk of future fractures, says Ian Reid, a professor of medicine at the University of Auckland. "I used to be a good boy who believed in calcium, but the evidence turned me into a calcium sceptic," he says.