Vitamin D deficiency rickets is characterized clinically by skeletal changes, muscle relaxation, and nonspecific psychoneurological symptoms. Patients with severe rickets can affect the digestive, respiratory, circulatory, and immune systems, as well as the intellectual development of the pediatric population. Clinically, it is divided into the initial, radical, recovery and sequelae phases. The initial period, the radical period and the recovery period are collectively referred to as the active period. Most of them start from about 3 months of age. During this period, psychoneurological symptoms are the main ones, and children have restless sleep, crying, and easy sweating, etc. After sweating, the scalp itches and shakes the head on the pillow, and occipital baldness appears. In addition to the initial symptoms, the child’s skeletal changes and motor function development are mainly retarded. 3-6 months old children with fingers pressed on the occipital and parietal bones, feel the skull sunken, with the hand relaxed and bounced back, called the ping-pong ball sign. 8-9 months old or more children’s skull is often square, fontanelle large and delayed closure, serious cases 18 months of age, the fontanelle has not yet closed. The junction of the ribs and rib cartilage on both sides is enlarged like beads, called rib beads. The middle of the sternum protrudes forward like a “chicken chest” or sinks into a “funnel chest”, and the lower edge of the thorax turns outward as “rib edge ectropion”; the spine protrudes backward and laterally; the legs of children who can stand and walk will In children who can stand and walk, the legs are bent inward or outward, i.e., “O” or “X” shaped legs. The child’s muscles and ligaments are lax and weak, and the abdomen is enlarged due to the weakness of the abdominal muscles, and the child has a “frog-like abdomen” when lying down. Teething is late, teeth are uneven, and dental caries easily occurs. Abnormal brain cortical function, slow formation of conditioned reflexes, indifferent expression, delayed language development, low immunity, easy to complicate infection and anemia. 3.Recovery period After certain treatment, all kinds of clinical manifestations disappear, muscle tone is restored, blood biochemical changes and X-ray performance also return to normal. 4.After-effects period Mostly seen in children after 3 years old, clinical symptoms disappear after treatment or natural recovery, and only severe rickets leaves different parts and degrees of skeletal deformities.