Effect of vitamin C on neutrophil function after high-intensity exercise

Background High-intensity exercise leads to an increased risk of upper resp iratory tract infections in athletes, which had been related to an exercise -induced impairment of neutrophil function. In this study, several indices of neutrophil function were analysed before and after a biathlon and the ef fect of oral vitamin C on neutrophil function was determined. Material and methods Six athletes took 2 g vitamin C daily for 1 week prior to a biathlon and four athletes did not take any supplementation. Neutroph il phagocytosis was analysed by fluorescence microscopy and flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil b actericidal ability was assessed by fluorescence microscopy. Reactive oxyge n production was analysed by flow cytometry. Catecholamines were analysed b y high-performance liquid chromatography. Results After high-intensity exercise there were significant reductions in the number of phagocytosed Escherichia coli per neutrophil and in neutrophi l bactericidal ability. There was a significant exercise-dependent increase of catecholamines. There was no difference between the two groups of athle tes. Conclusion These results do not support the concept that vitamin C suppleme ntation corrects neutrophil dysfunction after strenuous exercise.