Osteoporosis in steroid taking patients can be explained by all except

Ans c: (decreased .synthesis of vitamin D) Ref Goodwann& Gillmann chap 59Osteoporosis of glucocorticoid therapy is dose and duration dependent. Ribs and vertebrae are most common site of fracture.Mechanism:1. Inhibition of bone formation due to suppressive effect on osteoblast and stimulation of resorption due to effect on osteoclast mediated by changes in production of osteoprotegerin and RANK ligand2. decreased intestinal absorbtion of calcium-20 increase in parathormone-bone resorption3. increased excretion of calcium via kidney4. Inhibit gonadal steroid hormone