PTH increases ionic calcium concentration in the serum, acting primarily on bone and kidney cells through the type 1 PTH receptor. Interestingly, PTH stimulates bone formation when administrated intermittently but causes severe bone loss with continuous administration. Daily injections of PTH are used as the most promising anabolic agent in the treatment of severe osteoporosis. Elevated PTH is reported an independent risk factor for left ventricle hypertrophy.