Effect of iron deficiency on the digestive utilization of iron, phosphorus, calcium and magnesium in rats

The influence of the source of dietary Fe (ferric citrate alone or mixed with bovine blood at a proportion of 1:1 (v/v)) on the digestive utilization of Fe, P, Ca and Mg, and on haemoglobin regeneration efficiency (HRE) was investigated in control and Fe-deficient rats. Diet A contained (by analysis) 43.5 mg Fe/kg diet (as ferric citrate), and diet B contained 44.3 mg Fe/kg diet (ferric citrate-bovine blood). In Fe-deficient rats fed on diet A or B the apparent digestibility coefficient (ADC) of Fe increased by 42.3 and 45.7% respectively. The ADC of Ca and Mg decreased significantly in Fe-deficient rats regardless of the source of dietary Fe. The HRE increased by 72.9% in Fe-deficient rats fed on diet A, and by 91.1% in Fe-deficient animals fed on diet B. In Fe-deficient rats fed on Fe for 10 d the values of haematological variables approached normality. However, serum Fe remained low, indicating that Fe reserves were still depleted. A deficient dietary supply of Fe for 30 d did not significantly modify the numbers of circulating leucocytes.