Isolated defect of folic acid absorption associated with mental retardation and cerebral calcification.

By Pmu LANZKOWSKY, MARION E. Eiu.Arcnsox AND ALLAN I. BEzAN F OLIC ACID is of fundamental importance in numerous metabolic processes and is intimately involved in DNA, RNA and protein biosynthesis. A deficiency of this vitamin may arise by a number of well-studied mechanisms which include inadequate dietary intake, defective absorption as part of a generalized malabsorption syndrome, increased requirements or due to the presence of folic acid antagonists. The purpose of this paper is to describe a unique 18 year old feniale who has folic acid deficiency and megaloblastic anemia as a result of an isolated defect in the gastro-intestinal absorption of physiologic amounts of folic acid associated with a defect in the transport of folic acid from the plasma into the cerebrospinal fluid; mental retardation and cerebral calcification.