Copper Deficiency Anemia and Neutropenia Due to Ketogenic Diet.

Copper deficiency is an uncommon cause of hematologic abnormalities in children that is often overlooked or misdiagnosed. Although cases have been reported because of malabsorption syndromes or after gastrointestinal surgeries, we report a case of copper deficiency-associated anemia and neutropenia in a child because of dietary restrictions, specifically, transitioning from a formula-based ketogenic diet to a pureed food-based ketogenic diet. On copper supplementation, the patient's anemia and neutropenia resolved. To our knowledge, this report is the first revealing copper deficiency anemia and neutropenia developing because of a ketogenic diet.