Such high phosphorus in the blood can directly inhibit the secretion of 1α-hydroxylase by the kidneys, leading to obstacles in the production of renal active vitamin D3.[5] However, active vitamin D3 is an important component of intestinal absorption of calcium into the blood, so lack of it will cause hypocalcemia.[6] The reduction of activated vitamin D3 can make bones have varying degrees of resistance to parathyroid hormone (PTH), which will increase the compensatory secretion of PTH in the blood. Here, PTH is linked to Hypocalcemia.