[Mechanism of secondary hyperparathyroidism].

Renal osteodystrophy is an important concomitant disease in chronic renal failure. Secondary hyperparathyroidism cause high turnover bone. Hypocalcemia and phosphate retention stimulate the parathyroid and to proliferation of the parathyroid cells. In these days vitamin D deficiency, resistance to vitamin D, abnormality of sensitivity to calcium, direct effect of phosphorus , more severe form of parathyroid hyperplasia, abnormality of gene and increased skeletal resistance to PTH are pointed as cause of parathyroid hyperfunction.