Roles of citric and ascorbic acids in enteric iron absorption in rats

Abstract

The possibility that citric and ascorbic acids may promote intesitnal iron absorption by chelating the metal was investigated. By an in vitro method, iron, citric acid, and ascorbic acid transport were all found to be directly related to the concentration of citric or ascorbic acid in mucosal fluid. There appeared to be a limited capacity for ferric citrate transport, suggesting that this species may be transported by means other than passive diffusion. In vivo data indicated that the reducing action of ascorbic acid in the lumen is important, but that the vitamin also plays another role. This role may be chelation, an independent reductive action at the serosal surface, or another as yet undefined action.