Giving children foodsfortifiedwithcalciumto help build up their bones may be a waste of time, say experts.
The mineral is added to many breakfastcereals, snack bars and drinks as manufacturerswoothe parental market.
But scientists have found that such products do not produce significantly stronger bones, nor do they reduce the chance of a child sufferingfractures.
It is thought that calcium artificially added to food passes through the body too quickly to be properly absorbed and therefore fails to perform the same functions as foods which are naturally rich in calcium, such as milk, cheese andleafygreen vegetables.
It is now built into such things as Kellogg's Coco Pops, breakfast bars such as the Frosties Cereal and Milk bar, someTropicanaorange juices and even a calcium-enriched water called Danone Activ. The theory is that if children build strong bones it will protect them better against problems such asosteoporosisin later life. But the research casts doubt on the usefulness of such products.
Experts analyzed 19 studies where children aged between three and 19 were given extra calcium in their diet in this way. They then measured the impact by measuring their bone mineral density and mineral content.
The team found few significant increases in bone mass and none in the two bones which are most vulnerable to fracture - the lowerspineand upper part of thethigh.
A small impact was noted in bone density in the arm, but it cut the risk of fracture by just 0.2 per cent, according to the report published in the Cochrane Library. The influential publication is produced by the international health research organisation, the Cochrane Collaboration.
Lead researcher Professor Frank R Greer, of the University of Wisconsin, said the findings for children echo those seen in adult studies. "You can get some short-term improvements but as soon as you stop the supplements it goes right back to where it was," he said.
（来源：国际在线 英语点津 Annabel 编辑）