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 x 2 x 2 factorial experiment. Male Sprague-Dawley weanling rats were fed copper-deficient (Cu-, 0.42 microgram Cu/g) or copper-adequate (Cu+, 5.74 micrograms Cu/g) diets that contained one of two levels of iron (38 or 191 micrograms 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 microCi 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 less than 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 less than 0.02) in Cu- rats fed high iron. Among Cu- rats, ascorbic acid did not influence CCO but decreased hemoglobin by 17% (p less than 0.001), reduced the percentage of absorbed iron-59 in the erythrocytes by 91% (p less than 0.05) and depressed the percentage apparent absorption of iron (p less than 0.05). These results suggest that the effects of elevated dietary iron and ascorbic acid on iron utilization are influenced by copper status.