Effect of Diet on Iron Absorption in Iron-deficient Rats

Abstract

Effects of a number of dietary factors on iron absorption in iron-depleted female albino rats were tested by feeding 0.2 µCi of ³⁹Fe as an indicator with 20 or 80 µg of ferric ammonium sulfate iron added to 2 g of diet. Retained iron was determined as difference between total body count 2 hours and 9 days after ingestion of the radioiron. Inorganic iron retention was decreased by increasing the level of the salt mix in the diet and also influenced by the amount of calcium or phosphate it contained. When dietary carbohydrate was varied, the order of iron retention (high to low) was lactose, lactose and starch, sucrose, glucose, and starch with significant differences between diets. No significant differences were found between diets containing 5 to 40% casein. Iron absorption from biologically labeled corn was higher than that from liver or meat. However, iron retention from both liver and meat was significantly increased upon mixing with equivalent amounts of iron from corn. The addition of basal diet, lactose, starch, 40 µg of additional iron, or added radioactive iron had no effect upon the percentage of the iron dose retained from the labeled corn. Large doses of calcium carbonate and of inorganic iron decreased the percentage of iron retained from labeled hemoglobin but other dietary modifications tested did not alter hemoglobin iron retention. Large doses of hemoglobin did not depress inorganic iron retention.