or vitamin D deficiency
Disease of infancy and childhood characterized by defective bone growth due to lack of vitamin D .
Calcium phosphate is not properly deposited in the bones, which become soft, curved, and stunted. Early symptoms include restlessness, profuse sweating, lack of limb and abdominal-muscle tone, soft skull bones, and developmental delays. Muscles may cramp and twitch. Without early treatment, effects may include bowlegs, knock-knees, and beadiness where the ribs meet the breastbone. A narrow chest and pelvis can later increase susceptibility to lung diseases and impede childbirth. Treatment is with high-dose vitamin D supplementation, sunlight, and a balanced diet. Adding vitamin D to milk has reduced rickets in high-latitude areas where the skin cannot produce enough.