Copper status in rats fed diets supplemented with either vitamin E, vitamin A, or beta-carotene.

Copper status was measured in rats fed copper-adequate, purified diets supplemented with either vitamin E (250 IU/kg), vitamin A (40,000 IU/kg), or beta-carotene (2 g/kg). It was hypothesized that the extra intake of the antioxidants would spare vitamin C resulting in a decreased copper status as shown previously after supplementation with vitamin C. A significant increase in plasma ascorbate concentration was observed after beta-carotene supplementation, but not after supplemental vitamin E or vitamin A. Extra intake of either beta-carotene or vitamin A slightly, but significantly, raised plasma copper concentrations. Beta-carotene also slightly raised liver copper concentration. Supplemental vitamin E had no effect on plasma and liver copper concentrations. It is concluded that the observed relatively small effects of supplemental vitamin A and beta-carotene on copper status in rats are not mediated by changes in plasma vitamin C concentration.