The effect of 1 alpha-hydroxyvitamin D2 on calcium metabolism in glucocorticoid-treated rats

Intestinal calcium transport and renal calcium and phosphate excretion have been measured in normal and prednisolone-treated rats. Prednisolone treatment reduced intestinal calcium transport and increased phosphate excretion, causing a reduction in serum phosphate. Both 1 alpha-hydroxyvitamin D2 and 1 alpha-hydroxyvitamin D3 normalized phosphate excretion, whereas 1 alpha-hydroxyvitamin D3 was not fully effective in serum phosphate. Prednisolone treatment also caused a decreased bone density that was prevented both with 1 alpha-hydroxyvitamin D2 and 1 alpha-hydroxyvitamin D3. 1 alpha-hydroxyvitamin D2 appeared at least as effective as 1 alpha-hydroxyvitamin D3 in correcting the bone disturbance.