Calcium supplementation and postmenopausal bone loss.

A series of 103 early postmenopausal women completed a questionnaire about their dietary calcium intake and were then divided into three groups: those with an intake below 550 mg/day, those with an intake between 550 and 1150 mg/day, and those with an intake above 1150 mg/day. Thereafter they were given a daily supplement of 500 mg calcium for two years and had their bone mineral content measured every three months. Any changes found were taken as an estimate of bone calcium balance. All three groups showed a similar fall in bone mineral content over the two years, indicating that a calcium intake of 1000-2000 g daily is ineffective in preventing bone loss in the early menopause.