Effects of 1 alpha,25-dihydroxycholecalciferol on disuse osteoporosis in the dog: a histomorphometric study.

: Disuse osteoporosis was produced in dogs by immobilization of the left rear limb in a plaster cast. The trabecular bone volume of the calcaneus was then determined following treatment with 1 alpha,25-dihydroxycholecalciferol for 4 weeks with oral dosages of 60 to 240 ng/kg of body weight. The trabecular bone volume percentage of the immobilized calcaneus was in direct relation to the dosage of 1 alpha,25-dihydroxycholecalciferol.