Effect of estrogens and calcium carbonate on bone loss in postmenopausal women

Sixty postmenopausal women were placed in three groups - control, sex hormone-treated, and CaCO₃-treated - and followed for 2 years. Skeletal mass decreased by 1.18%/year in the control group, 0.15%/year in the hormone group, and 0.22%/year in the CaCO₃ group by radiogrammetry; and 2.88%/year in the control group, 0.73%/year in the hormone group, and 1.83%/year in the CaCO₃ group by photon absorptiometry. The treatment groups differed significantly from the control group except for photon absorptiometry in the CaCO₃ group. Bone accretion and resorption decreased in the treatment groups as measured by calcium tracer kinetics, resorption more so than accretion. The authors conclude that [1] these techniques are sufficiently sensitive to detect age-related bone loss; [2] postmenopausal sex-hormone replacement measurably decreases age-related bone loss by suppressing bone turnover, resorption more than accretion; and [3] calcium supplements produce the same effect but at the dose the authors used were slightly less effective.