Daily supplements of calcium and vitamin D reduce the risk of fractures in women and men of all ages, even if they've suffered previous fractures, but vitamin D supplements alone don't offer significant protection.

There's a growing consensus that a combination of calcium and vitamin D is more effective than vitamin D alone in preventing nonvertebral fractures. To determine if calcium plus Vitamin D actually reduces the risk of fractures, researchers analysed data from 68,517 people, average age 70, who took part in seven studies that looked at the effect vitamin D or vitamin D plus calcium had on reducing fractures.

The analysis revealed that vitamin D given alone in doses of 10 micrograms to 20 micrograms per day doesn't prevent fractures. However, calcium and vitamin D given together reduce the risk of hip fractures, total fractures and possibly vertebral fractures.

Further research is, however, needed to determine the most effective dose, treatment duration and method of taking the calcium/vitamin D combination.