Effect of vitamin C supplementation on neutrophil function in male judoists during a training camp

Abstract

    We examined the effects of vitamin C supplementation on neutrophil function during exercise loading. Neutrophil functions, namely the reactive oxygen species (ROS) production capability, neutrophil phagocytic activity (PA) and serum opsonic activity (SOA) were measured before and after a 2-hour unified loading exercise (ULE) both before and after a 7-day intensified training camp for 22 male judoists. The parameters were assessed neutrophil count, myogenic enzymes, vitamin C in serum, SOA, PA, ROS production capability, body composition, and so on. Subjects were randomly assigned to two groups; the VC group (daily diet supplementation of 1,500 mg vitamin C) and the Control group (no vitamin C supplementation). The post-camp pre-ULE vitamin C level was higher in the VC group than in the Control group, though no such difference was seen at pre-camp. As for neutrophil function, although the typical changes seen following a single bout of normal exercise, namely an increase in SOA and ROS, and a decrease in PA, were recorded following the pre- and post-camp ULEs in both groups, significant difference in change rates were not seen between both groups. In conclusion, vitamin C supplementation had no significant influence on changes in neutrophil function.