CALCIUM SUPPLEMENTATION WITH AND WITHOUT HORMONE REPLACEMENT THERAPY TO PREVENT POSTMENOPAUSAL BONE LOSS

Objective: To determine whether augmentation of dietary calcium is eff ective in the prevention of early postmenopausal bone loss. Design: Th ree-arm, placebo-controlled, randomized parallel trial. The study dura tion was 2.9 +/- 1.1 (SD) years. Setting: General community. Participa nts: 118 healthy, white women 3 to 6 years after spontaneous menopause , recruited by community announcement. Interventions: Random allocatio n to daily intake of 1700 mg of calcium (calcium carbonate given in di vided doses with meals); placebo; or conjugated equine estrogens (0.62 5 mg; days 1 to 25), progesterone (10 mg; days 16 to 25), and 1700 mg of elemental calcium daily. Each participant received 400 IU of vitami n D daily. Main Outcome Measures: Total body calcium measured by delay ed gamma neutron activation analysis and whole-body counting; bone min eral density of the spine, femur, and radius measured by photon absorp tiometry. Results: Bone mineral density declined in the placebo group for the lumbar spine (-2.1%/y; 95% CI, -3.3 to -0.9), femoral neck (-2 .0%/y; CI,-2.6 to -1.2), trochanter (-1.6%/y; CI, -2.4 to -0.8), Ward triangle (-2.7%/y; CI, -3.7 to -1.7), and total body calcium (-2.0%/y; CI, -2.2 to -1.8). Rates of change were intermediate for calcium augm entation compared with placebo and estrogen-progesterone-calcium but s tatistically significant compared with placebo for total body calcium (-0.5%/y; CI, -0.9 to -0.1; P = 0.006) and the femoral neck (-0.8%/y; CI, -1.4 to -0.2; P = 0.03). Conclusions: Although less effective than estrogen-progesterone-calcium, calcium augmentation alone significant ly retards bone loss from the femoral neck and improves calcium balanc e in recently postmenopausal women. Dietary calcium augmentation shoul d be recommended as a strategic option in helping to prevent early pos tmenopausal bone loss.