Megaloblastic Anaemia of Infancy and Vitamin B12

SUMMARY The haematological status of 30 infants with a syndrome characterized by satisfactory growth, abnormal pigmentation, developmental retardation, hypotonia of muscles, hepatosplenomegaly, with or without tremors, has been studied. Anaemia of a moderate degree was seen in all. All but four had megaloblastic erythropoiesis. Serum vitamin B12 levels were below 100 pg./ml. By increasing the infants' intake of vitamin B12>, by raising the concentration of the vitamin in maternal milk, megaloblastic erythropoiesis could be corrected to normoblastic erythropoiesis. The other clinical manifestations of the syndrome also responded to the administration of vitamin B12 to varying degrees.