EFFECTS OF IRON REPLENISHMENT ON IRON, CALCIUM, PHOSPHORUS AND MAGNESIUM-METABOLISM IN IRON-DEFICIENT RATS

We investigated the effect of Fe deficiency on the nutritive utilizati on of Fe, Ca, P and Mg in rats. Aside from the well known depletion of Fe in liver, femur and sternum with low values of Hb, Fe deficiency i mpaired Ca, P and Mg metabolism at different degrees. Iron deficiency altered Mg absorption, lowered the concentration of Ca in the liver, f emur and sternum, raised the concentration of P and Mg in the liver, a nd decreased P in the femur. The altered status was not completely rec tified by iron supplementation as the animals were still slightly anem ic at the end of the study. The second purpose of the study was to eva luate the ability of three iron compounds (ferric citrate, ferrous sul fate and ferrous ascorbate) to correct the undesirable effects of Fe d eficiency. Ten days after treatment with these diets, Fe-deficient rat s still had reduced Mg absorption, especially those fed ferric citrate . The concentrations of hemoglobin approached normal values in all gro ups; however, serum Fe remained low, indicating that Fe reserves were still depleted. Hepatic and femoral Fe concentrations were also lower in all Fe-deficient groups regardless of the diet given, compared with their respective controls, whereas Fe concentrations in the sternum i ncreased significantly with all three diets, suggesting an increase in erythropoiesis. The concentration of Ca, P and Mg in liver approached normal values, and appeared to normalize in the femur, except that Ca and P concentrations remained low with the citrate diet. In the stern um, a site assumed to have higher requirements for these minerals, the concentrations of Ca, P and Mg also increased. These findings indicat e that Fe is involved in the bone mineralization, and that in physiolo gical terms, Fe interacts favorably with Ca, P and Mg metabolism, sinc e Fe deficiency altered the status of these metals. These findings als o suggest that ferrous ascorbate and ferrous sulfate were more effecti vely absorbed than was ferric citrate.