Effect of vitamin C on copper and iron metabolism in the guinea pig.

Although interaction of vitamin C, copper and iron have been studied in several species, little is known about these interactions in species which require the vitamin in the diet. Young male Hartley guinea pigs were fed a basal diet, or a basal diet and supplemented daily with vitamin C, p.o. Pharmacologic doses (25 mg per 100 g BW per day) of vitamin C resulted in two-to-three-fold decreases in liver copper, when compared with those receiving normal (0.5 mg per 100 g BW per day) intakes. Under conditions of vitamin C deficiency, serum copper and ceruloplasmin were elevated along with liver copper. Serum and hepatic iron levels, hepatic microsomal cytochrome P-450 and cytochrome b5, and blood heme parameters all appeared to be directly related to vitamin C intake, i.e. the iron and heme parameters increased as the vitamin dose increased. These data are consistent with the hypothesis that interaction between vitamin C, copper and iron influence normal heme formation through the oxidation/reduction of iron and/or by regulating iron absorption and availability at the gut level.