The main manifestations of vitamin D deficiency are children's irritability and crying, night sweating, sleep disturbance, occipital baldness, muscle relaxation and delayed development. Because of the low calcium and phosphorus content in the bone, the epiphyseal cartilage overgrowth, the bones lack of normal hardness, the long bones are often deformed, the formation of "O" or "X" shaped legs, also known as the legs; the knee is enlarged to form the "atresia knee The knee is enlarged to form "atresia knee"; the combination of ribs is enlarged to form "rib beads"; the wrist and ankle joints are enlarged, which is called rickets bracelet. Due to the softening of the skull, the head is deformed, with the frontal, parietal, and occipital bones bulging outward, forming a "square head"; the fontanel is softened at the edges, the bone gap is widened, and the atresia is delayed; the sternum protrudes to form a "chicken breast"; the diaphragm pulls the softened ribs to form a depression called the The diaphragm pulls on the softened ribs, forming a depression called a "costochondral groove". In addition, in more severe cases of rickets, there may be enlargement of the liver and spleen and anemia.

The key to treating vitamin D deficiency is to supply enough vitamin D and adequate sun exposure. The skin contains a dehydrocholesterol substance, after exposure to ultraviolet light in the sun, can become vitamin D3, which is the main source of vitamin D in the human body. Prevention is best started during pregnancy with appropriate calcium and vitamin D. Children can be given vitamin D 15 days after birth at 50,000 to 100,000 IU per day until 1 year of age. After a child reaches the age of one month, he or she can be taken outdoors for sunlight exposure for 10 to 15 minutes at first, and then gradually extend the time, preferably for more than 2 hours a day outdoors. If sunbathing indoors, open a window. In the winter and spring of the birth of small children, premature babies, twin babies, the beginning of the time to carry out the outdoors should be delayed.

Mildly ill infants who are exposed to sunlight and improved feeding, especially in the summer months, can be cured even without medication. Treatment with vitamin D preparations, the initial oral daily vitamin D 0.5 ~ 10,000 international units, later oral 15,000 ~ 40,000 international units. Do not use cod liver oil if the dosage is high to avoid vitamin A toxicity. Surprise treatment can also be used, intramuscular injection of vitamin D2 or vitamin D3, the milder one time intramuscular injection of vitamin D3.3 million units of vitamin D or vitamin D2.4 million units; the more serious can be intramuscular injection of vitamin D3.6 million units of vitamin D or vitamin D2.8 million units. While treating with vitamin D, calcium tablets or calcium powder should be supplemented with 1.5 to 2 grams per day for 1 month, and when intramuscular vitamin D is injected, it is best to give calcium, 3 grams per day or 5% calcium chloride 5 ml 3 times per day orally 3 days before the treatment.