A large phase 3 clinical trial found that strontium ranelate, a drug used to treat osteoporosis in the 1950s, reduced vertebral fractures and increased bone mineral density in postmenopausal women with osteoporosis, as reported in a recent issue of the New England Journal of Medicine. Also, bone loss was lessened and bone formation was greater in women taking strontium ranelate. The drug had fallen out of favor several decades ago due to concerns about its effects on bone mineralization and on the synthesis of vitamin D. Now, researchers suggest that those results might have been due to calcium-deficient diets. The recent trial included 1649 postmenopausal women with osteoporosis who had had at least 1 vertebral fracture. The women received either 2 g of strontium ranelate daily or placebo. All participants also received vitamin D and calcium supplements. In a year, the women taking strontium ranelate had 49% fewer vertebral fractures than did the placebo group. At the 3-year mark, the women taking strontium ranelate also showed increased bone density.