Vitamin D3 and Calcium to Prevent Hip Fractures in Elderly Women

Background. Hypovitaminosis D and a low calcium intake contribute to increased parathyroid function in elderly persons. Calcium and vitamin D supplements reduce this secondary hyperparathyroidism, but whether such supplements reduce the risk of hip fractures among elderly people is not known. Methods. We studied the effects of supplementation with vitamin D, (cholecalciferol) and calcium on the frequency of hip fractures and other nonvertebral fractures, identified radiologically, in 3270 healthy ambulatory women (mean [+SD] age, 84+6 years). Each day for 18 months, 1634 women received tricalcium phosphate (containing 1.2 g of elemental calcium) and 20 yg (800 IU) of vitamin D,, and 1636 women received a double placebo. We measured serial serum parathyroid hormone and 25hydroxyvitamin D (25(OH)D) concentrations in 142 women and determined the femoral bone mineral density at base line and after 18 months in 56 women. Results. Among the women who completed the 18HE risk of hip fractures and other nonvertebral fractures increases in the elderly, reaching nearepidemic levels in many developed countries. Although many factors contribute to such fractures, the most important causes are a reduction in bone mass and an increased frequency of falls. Bone density progressively decreases with age.'? The decrease can be explained, at least in part, by increased parathyroid hormone secretion®® resulting from vitamin D deficiency and low calcium intake that are not compensated for by an increase in 1,25-dihydroxyvitamin D (1,25(OH),D) production.® Whether vitamin D or calcium supplements, or both, retard bone loss and reduce the rate of fractures among elderly people (those more than 70 years of age) is not known. In a previous study, we found that six months of supplementation with calcium (1 g per day) and vitamin D, (ergocalciferol; 800 IU per day) reduced the biochemical indexes of secondary hyperparathyroidism in elderly persons.’ The present study was undertaken to determine whether vitamin D, (cholecalciferol) and calcium supplements decrease the frequency of nonvertebral fractures, particularly fractures of the femoral neck, among ambulatory elderly women living in nursing homes.