Abstract
The effects of dietary supplements of copper (0.02%), iron (0.04%) and zinc (0.75%) on growth and iron metabolism of rats were observed. Although diets with elevated levels of iron significantly lowered uptake, dietary zinc or copper had no significantly effect on absorption of orally administered radioactive iron, 96 hours prior to death. Diets high in zinc did, however, significantly lower retention of chronically administered dietary radioactive iron as well as decrease liver iron stores. The data suggest that iron absorbed from the digestive tract was apparently following a normal metabolic pathway after 96 hours, but later deviated significantly under conditions of zinc toxicity. Copper levels were not significantly altered under the conditions of these experiments.