Disorders of bone metabolism in severely handicapped children and young adults.

There is a high prevalence of vitamin D deficiency in the severely handicapped pediatric population. Because many of these patients have growth deficiencies, they may not demonstrate wide growth plates commonly seen with vitamin D deficiency. There is also a high prevalence of anticonvulsant use in these patients, and its exact impact is not clear because of the variety of its effects and presentations. Calcium, phosphate, and alkaline phosphatase are not useful as indicators of vitamin D deficiency, and vitamin D metabolites must be measured directly. Patients with low vitamin D levels respond to treatment, including nutritional support and added sunlight exposure. The overall nutritional status of this population may be reflected in their metabolic bone disease and small stature.