Alkaline phosphatase above 300 units per liter in children requires further testing to determine the cause to determine the risk of diseases such as rickets and hypoparathyroidism which may eventually lead to bone deformities. Alkaline phosphatase in children reflects the child’s bone metabolism, which can reflect parathyroid function, liver and gallbladder disease, calcium and phosphorus metabolism in the body, and bone growth. The normal value for children younger than 12 years of age is less than 500 units per liter, while the normal range for children 12 to 15 years of age is 40 to 150 units per liter. The increase in alkaline phosphatase in children may be due to physiologic conditions, as alkaline phosphatase is associated with height, bone growth, and postprandial secretion of fat. Therefore, the increase in height in children under 12 years of age during the growth period is a normal phenomenon that does not require special treatment, but it is important to rule out diseases. Diseases of the hepatobiliary system, such as obstruction of the hepatic and biliary ducts, can cause an increase in alkaline phosphatase, so an increase in alkaline phosphatase can be further investigated to determine whether there is a disease of the liver or gallbladder. Bone disorders such as rickets, osteomalacia, or disorders of parathyroid secretion can also cause elevated levels. Therefore, children with a blood level of 300 units per liter can undergo liver and gallbladder tests, bone mineral density, and calcium and phosphorus tests to further determine whether there is a disease and to treat it appropriately.