Eldecalcitol is a drug used in Japan for the treatment of osteoporosis. It is an analog of vitamin D.This condition often results in bone fractures due to abnormally low bone mass density, and is a leading cause of disability, especially among developed countries with longer average life spans. Osteoporosis is more common in women than with men. Eldecalcitol can be used for the treatment of hypocalcaemia or osteoporosis. Calcium absorption increases with the presence of eldecalcitol by the body, occurring in the intestines, which is useful for those who have low calcium levels. Eldecalcitol is more often used due to its effects to treat osteoporosis. In the aging population, the bone matrix becomes weakened through untreated osteoporosis. This leads to an increased risk of severe fractures that include spinal and hip fractures in addition to vertebral and wrist fractures.