[The usefulness of calcium and vitamin D supplementation after the Women's Health Initiative trial].

Three recently published randomized controlled studies on the effects of calcium and vitamin D on fracture risk from the UK and the USA were critically reviewed. We found problems related to their external validity compromising their transferability to Denmark. Furthermore, study power was limited because of the selection of low-risk patients, problems with compliance and persistence, and supplementation with calcium and vitamin D outside the protocol. Two recent meta-analyses including the three studies supported the continuous use of calcium and vitamin D to prevent fractures in the elderly.