<prompt> PTH does not cause -Maintains serum Ca2Ca2 retentionDecreased PO43- excretionMay cause osteolysis  <response>: Effect of parathyroid hormoneOn calciumIt increases serum calcium level byIncreases resorption of calcium from bone This is the most prominent action.Stimulates reabsorption of Ca by kidneyStimulates renal activation of it. D which increases intestinal absorption of calcium On PhosphorusDecrease the level of PO43- in Serum by decreasing PO43- reabsorption in the kidney. 