A comparison of bone loss from different skeletal sites during acute calcium deficiency in mice.

Severe Ca deficiency was produced by the combined stresses of a Ca-deficient diet and lactation in female mice. Alveolar bone loss was assessed by changes in alveolar crest height and in quantity of supporting trabecular bone. Changes in the femur were measured by changes in mineral content and in the cross-sectional area of the midshaft region, and in vertebrae by changes in mineral content. A similar decrease in bone was observed in all sites during progression of Ca deficiency with a similar increase during recovery. Maximum bone loss amounted to more than 50 per cent. Alveolar bone loss was characterized by a reduction in trabecular bone without loss of alveolar crest height.