Osteoporosis is a major public health problem that will become increasingly important as our population ages. It leads to fractures that deeply affect the patients' quality of life. Osteoporosis is recognised as a leading factor in healthcare cost worldwide. For years, experts have recommended hormone replacement therapy (HRT), consisting of oestrogen with or without progestin, as the first-line therapy to prevent bone loss in postmenopausal women. Recently published randomised, controlled trials and well-designed meta-analyses confirm that HRT has both advantages and disadvantages. The advantages include prevention of osteoporotic fractures and colorectal cancer. The disadvantages are the resulting adverse effects such as coronary artery disease, stroke, thromboembolic events, breast cancer and cholecystitis. In the light of these findings, medical associations recommend against the routine use of oestrogen and progestin for the prevention of chronic conditions in postmenopausal women. HRT, administered for the prevention of fractures in all young postmenopausal women, would have an additional cost/year of life gained that is too expensive. However, this strategy seems to be cost-effective when young postmenopausal women at high risk for fractures are selected. Even if this strategy seems attractive, the adverse effects of HRT are not acceptable. This situation implies that other treatments must be found to prevent or treat osteoporosis. Among them, calcium and vitamin D were shown to be cost-saving in osteoporosis and even costs-effective in osteopoenia in young postmenopausal women.