With the Technical Assistance of DIANA WASSERMAN STEINHOUSE

gastrointestinal tract following large doses of iron produces a prompt and brisk rise in the level of the serum iron.1-5 Currently it is said that ferrous salts are more readily absorbed than ferric salts2-7 and that both are less readily absorbed from the gastro-intestinal tract of persons with achiorhy-dna.2’3’7’9 The presence of free hydrochloric acid is held to be necessary for the conversion of ferric to ferrous iron,37 in which state the iron is absorbed, and to prevent the precipi-tation of insoluble and nonabsorbable ferric salts.3”#{176} A pH of 5 of the gastric content is believed to be the critical level for the con-version of fernic to ferrous iron. The absorp-tion of iron is through the mucosa of the stomach and duodenum3’5’11 and this corre-sponds closely to the distribution of ferritin in the gut 12 However, as a striking exception to part of this hypothesis, it should be em-phasized that the absorption of iron from the gastrointestinal tract of persons having Addi-sonian pernicious anemia is often prompt and adequate.2”3 More recent studies using the technique of determination of the ab-sorption of radioactive iron from the stomach From the Departments of Medicine and Psychiatry