Rickets is a disease, and its full name is Nutritional Vitamin D Deficiency Rickets. It is caused by a lack of vitamin D in children, leading to a disorder in calcium and phosphorus metabolism in the body. It is a chronic nutritional disease characterized by bone lesions. Its typical manifestation is incomplete mineralization of the growing long bone ends and bone tissue. The symptoms include abnormal development of the bones. Generally, without timely and effective intervention, it may lead to conditions such as pigeon chest, or S-shaped or O-shaped legs, which can seriously affect the child's life later on.