Anemia associated with changes in iron and iron-59 utilization in copper deficient rats fed high levels of dietary ascorbic acid and iron

The influence of dietary copper, iron, and ascorbic acid on iron utilization was examined in a 2×2×2 factorial experiment. Male Sprague-Dawley weanling rats were fed copper-deficient (Cu-, 0.42 μg Cu/g) or copper-adequate (Cu+, 5.74 μg Cu/g) diets that contained one of two levels of iron (38 or 191μg Fe/g) and ascorbic acid (0 or 1% of the diet). These eight diets were fed for 20 d, and rats received an oral dose of 4 μCi iron-59 on d 15. Compared to Cu+ rats, the Cu− rats had 27% lower hemoglobin levels with 45, 59, and 65% lower cytochrome c oxidase (CCO) activities in the liver, heart, and bone marrow, respectively (p<0.0001). High dietary iron or ascorbic acid did not alter hemoglobin in Cu+ rats. However, hemoglobin was 23% lower in Cu− rats fed the highest, rather than the lowest levels of iron and ascorbic acid. Liver CCO was decreased (p<0.02) in Cu− rats fed high iron. Among Cu− rats, ascorbic acid did not influence CCO but decreased hemoglobin by 17% (p<0.001), reduced the percentage of absorbed iron-59 in the erythrocytes by 91% (p<0.05) and depressed the percentage apparent absorption of iron (p<0.05). These results suggest that the effects of elevated dietary iron and ascorbic acid on iron utilization are influenced by copper status.