MICROANATOMY

Detailed explanation-1: -Calcitonin decreases calcium levels by blocking the breakdown of bone calcium and by preventing your kidneys from reabsorbing calcium. In other words, it encourages calcium loss through your kidneys.

Detailed explanation-2: -The major target site for calcitonin is bone, where it inhibits osteoclastic bone resorption. The effects of calcitonin in bone are transitory, which has limited the usefulness of calcitonin as a treatment for hypercalcemia. At high doses, calcitonin may promote urinary calcium excretion.

Detailed explanation-3: -Calcitonin is known to stimulate renal 1, 25 (OH)2 vitamin D (1, 25D) production at a site in the proximal tubule different from parathyroid hormone and hypophosphatemia.

Detailed explanation-4: -Parathyroid hormone is directly involved in the bones, kidneys, and small intestine. In the bones, PTH stimulates the release of calcium in an indirect process through osteoclasts which ultimately leads to the resorption of the bones.