The hormone involved in the regulation of calcium and phosphorus metabolism is secreted by the gland called
Parathyroid
The parathyroid glands are small, oval bodies that are usually four in number which lie at the back of thyroid glands. They secrete a hormone called as parathormone or parathyrin. It regulates the level of calcium in the blood plasma. Parathormone and a thyroid hormone called calcitonin work antagonistically (they work in opposite ways i.e. if one increases the calcium and phosphate levels, the other will decrease) to regulate the plasma calcium and phosphate levels.