The two hormones which results in the fluctuation of Ca++ levels are:

• Thyrocalcitonin (TCT): It lowers the levels of Ca++ and K+ in the blood and promotes the formation of bone in the body.

• Parathyroid hormone: When the Ca++ in our blood goes too low, the parathyroid glands make more parathyroid hormone (PTH). The Increased levels of Parathyroid hormone (PTH) cause the bones to release their Ca++ into the blood.