Effect of estrogen/gestagen and 24R,25-dihydroxyvitamin D3 therapy on bone formation in postmenopausal women

The effect of two different estrogen/gestagen regimens and 24R,25-(OH)2-cholecalciferol on bone formation was studied in a randomized trial with 144 healthy postmenopausal women. Urinary excretion (UE) of 99m-technetium-diphosphonate and serum alkaline phosphatase (AP) was determined before and then once a year for 2 years of treatment. Both estimates of bone formation showed highly significant decreases (p less than .001) to normal premenopausal levels in women receiving unopposed 17 beta-estradiol or in a sequential combination with progestagen, whereas unchanged high values were found in the groups receiving 24R,25-(OH)2D3 and placebo. The data show that bone turnover increases in early postmenopausal women concomitantly with the loss of bone mass, and that hormonal substitutional therapy normalizes the total skeletal turnover as well as preventing bone loss.