It has been demonstrated repeatedly that a satisfactory hemoglobin response in cases of hypochromic anemia ensues with the administration of large amounts of iron,1 but it is recognized that the amount of iron so administered is greatly in excess of that utilized in hemoglobin regeneration. We2 have shown that from 14 to 71 per cent of the administered iron is retained by the body when 3 Gm. of iron and ammonium citrates (yielding approximately 500 mg. of metallic iron) is given daily by mouth. Only a small portion of this (1.2 to 3.4 per cent) is utilized in the building of hemoglobin.
The hemoglobin response to small amounts of iron has been found to be less satisfactory, although the amount of iron would seem to be adequate for hemoglobin regeneration if it were properly absorbed from the gastro-intestinal tract. The present study was undertaken to determine the amount