Calcium supplementation with and without hormone replacement therapy to prevent postmenopausal bone loss

Ann Intern Med. 1994 Jan 15;120(2):97-103. doi: 10.7326/0003-4819-120-2-199401150-00001.


Objective: To determine whether augmentation of dietary calcium is effective in the prevention of early postmenopausal bone loss.

Design: Three-arm, placebo-controlled, randomized parallel trial. The study duration was 2.9 +/- 1.1 (SD) years.

Setting: General community.

Participants: 118 healthy, white women 3 to 6 years after spontaneous menopause, recruited by community announcement.

Interventions: Random allocation to daily intake of 1700 mg of calcium (calcium carbonate given in divided doses with meals); placebo; or conjugated equine estrogens (0.625 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 vitamin D daily.

Main outcome measures: Total body calcium measured by delayed gamma neutron activation analysis and whole-body counting; bone mineral density of the spine, femur, and radius measured by photon absorptiometry.

Results: Bone mineral density declined in the placebo group for the lumbar spine (-2.1%/y; 95% Cl, -3.3 to -0.9), femoral neck (-2.0%/y; Cl, -2.6 to -1.2), trochanter (-1.6%/y; Cl, -2.4 to -0.8), Ward triangle (-2.7%/y; Cl, -3.7 to -1.7), and total body calcium (-2.0%/y; Cl, -2.2 to -1.8). Rates of change were intermediate for calcium augmentation compared with placebo and estrogen-progesterone-calcium but statistically significant compared with placebo for total body calcium (-0.5%/y; Cl, -0.9 to -0.1; P = 0.006) and the femoral neck (-0.8%/y; Cl, -1.4 to -0.2; P = 0.03).

Conclusions: Although less effective than estrogen-progesterone-calcium, calcium augmentation alone significantly retards bone loss from the femoral neck and improves calcium balance in recently postmenopausal women. Dietary calcium augmentation should be recommended as a strategic option in helping to prevent early postmenopausal bone loss.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Analysis of Variance
  • Bone Density
  • Calcium Carbonate / analysis
  • Calcium Carbonate / therapeutic use*
  • Calcium, Dietary / analysis
  • Calcium, Dietary / therapeutic use*
  • Combined Modality Therapy
  • Estrogen Replacement Therapy*
  • Estrogens, Conjugated (USP) / therapeutic use
  • Female
  • Humans
  • Middle Aged
  • Osteoporosis, Postmenopausal / metabolism
  • Osteoporosis, Postmenopausal / prevention & control*
  • Progesterone / therapeutic use


  • Calcium, Dietary
  • Estrogens, Conjugated (USP)
  • Progesterone
  • Calcium Carbonate