In urine the vitamin C values obtained by using the α,α'-dipyridyl method were often elevated due to urinary reducing substances. Ascorbate oxidase is highly specific for oxidizing vitamin C. An improved method using ascotbate oxidase is described for the determination of urinary vitamin C. The method is specific, sensitive and reproducible, and it is also rapid and simple enough for many measurements. Using the method the urinary vitamin C was determined for 176 male students, 61 female students, 352 male staff members and 81 female staff members of our university. There was little difference in overall frequency distribution of vitamin C values in the four groups. However, somewhat lower vitamin C levels were found in students compared with staff members, and in male groups compared with female groups.
