The main manifestation of rickets is the change of bones in the fastest growing area, and it can affect the muscle development with the change of nerve excitability. Early manifestations are usually seen in infants less than 6 months of age, especially in those less than 3 months of age, and are characterized by increased neural excitability, such as irritability, fussiness, and shaking of the head due to sweaty scalp irritation. Infants with early vitamin D deficiency that continues to worsen without treatment enter the active phase, which presents with the typical skeletal changes of hyperparathyroid hormone function and calcium and phosphorus metabolism derangements, primarily in the cranial lesions, which manifest as cranial softening. The fontanel is large and closes late. After 6 months of age, the softening of the skull disappears, and a square skull may appear. The chest may show rib beading, chicken chest, funnel chest, and Hao’s groove. In severe cases, the spine can have backward or lateral curvature, and the limbs can have bracelets, anklets, x-shaped legs, o-shaped legs, and so on. In more serious rickets, children can also have ligamentous laxity, manifested by decreased muscle tone and strength, accompanied by malnutrition and anemia, and can have liver and spleen enlargement. After active treatment and exposure to sunlight, the signs and symptoms can be gradually reduced or disappeared. For children over two years old, if they are seriously deficient in vitamin D, they can be left with different degrees of bone deformity. Once rickets is diagnosed, the active period must be actively controlled to prevent bone deformities. As long as children have enough outdoor activities and take vitamin D supplements on time, it is possible to completely prevent rickets from occurring.