Hypercalcemia from hypervitaminosis A in a child with autism.

Objectives Vitamin A is essential for normal cellular physiology and is often taken as a dietary supplement. Hypervitaminosis A can lead to hypercalcemia by increasing osteoclasts and subsequent bone resporption. Dietary supplements including vitamin A are new popular treatment stategies for autism. Case presentation We report a five-year old boy with autism spectrum disorder presenting with severe abdominal pain and bilateral lower extremity pain, who was found to have persistent hypercalcemia due to hypervitaminosis A. The patient ingested over 700 times the recommended intake of Vitamin A per day for age. Retention of vitamin A in the liver and adipose tissue causes toxic levels of retinoids and hypercalcemia. Conclusions Acute treatment included intravenous rehydration, furosemide, and calcitonin. Pamidronate was the definitive treatment for hypercalcemia from hypervitaminosis A due to its osteoclast inhibition and long biologic half-life. Parents should be counseled on risks of toxicity and absence of evidence showing benefits of vitamin A therapy for autism.