Vitamin D deficiency rickets in a toddler.

Nutritional rickets is the failure of normal bone formation in children, caused by vitamin D deficiency, low calcium intake, or a combination of both. In the United States, prolonged breastfeeding without vitamin D supplementation is a major risk factor. Increasing awareness of the rationale for and importance of vitamin D supplements for all breastfed infants and children should reduce the incidence of vitamin D deficiency rickets and prevent bone deformity.