Osteotriol is one of the most important substances that are active after the degradation of vitamin D3 and is mainly synthesized within the kidneys. If kidney function decreases, this can lead to a decrease in the synthesis of osteotriol, which can lead to calcium loss. The main role of osteotriol is to promote the absorption of calcium in the intestine and to promote the calcification of bone, which has a particularly important role in the intake of bone. Osteotriol can treat rickets due to vitamin D3 deficiency and hypocalcemia due to decreased parathyroid function. The use of osteotriol significantly increases the blood calcium concentration, improves calcium intake, and enhances calcium deposition and bone calcification.