Iron is an essential nutrient for a number of cellular activities including oxygen transport, electron transfer, and gene regulation. However, iron is potentially toxic via its redox reactions which generate reactive oxygen species (ROS). Oxidative damage to biomolecules can be modulated by antioxidants such as ascorbic acid (AA). However, it is well known that in the presence of redox-active iron, AA can act as a pro-oxidant in vitro and contribute to the formation of hydroxyl radicals.  Based on the possible pro-oxidant interaction of iron and AA, we evaluated the manifestations of supplementation of iron associated with the ascorbic acid. Twelve non-smoking male healthy volunteers, aged between 20 and 31 years were used in the study. The volunteers were supplemented with a single dose containing 2g of ascorbic acid in the first group, 150mg of iron in the second group and 2g of ascorbic acid plus 150mg of iron in the third group. The fourth group was the control group that did not consume any supplement. The determination of plasmatic iron and ferritin was made through kit donated by the laboratory Roche. Thiobarbituric acid reactive substances (TBARS), catalase (CAT), ascorbic acid, delta-amino levulinate dehydratase (ALA-D) and SH were measured in blood of the volunteers. The results showed that there were no significant differences in all the determinations. Vitamin C levels were increased at 2, 5 and 24 hours after vitamin C or vitamin C plus iron ingestion. Plasmatic iron level was increased at 2 hours after iron ingestion and 2, 5 hours in the group vitamin C plus iron. The results of this study indicate that simultaneous supplementation with vitamin C and iron was not associated with increased indexes of oxidative stress.  Thus the present study does not support the hypothesis that the combination of high plasma concentrations of AA and iron, or iron alone, causes oxidative damage in vivo. However, further studies are required to determine if iron and AA interactions could have a pro-oxidant effect in vivo.