Bioavailability of Copper Bound to Dietary Fiber in Mice and Rats

The bioavailability of copper (Cu) was compared in mice or rats fed diets containing wheat bran‐bound Cu and adequate Cu (unbound) or deficient Cu with cellulose or wheat bran. Cardiac and hepatic Cu content were comparable in mice fed bran‐bound or adequate Cu and greater than mice fed deficient Cu. Cardiac Cu content was comparable in rats fed bran‐bound Cu and adequate Cu and greater than rats fed deficient Cu. Hepatic Cu content, however, was less in rats fed bran‐bound Cu than adequate Cu and greater in both than deficient Cu. Both rats and mice utilized dietary Cu bound to wheat bran, suggesting that mineral‐fiber interactions may not decrease bioavailability when dietary mineral is adequate. Tissue Cu content in Cudeficiency was lower in animals fed wheat bran compared to cellulose, suggesting that the type of fiber may exacerbate effects of mineral deficiency.