The effect of vitamin C on the metabolic parameters of experimental diabetes mellitus

The role of vitamin C on diabetes mellitus is unknown. The purpose of this study was to examine the effect of oral administration of vitamin C on some of the metabolic parameters of diabetic rats. Diabetes was induced by intraperitoneal injection of STZ (60 mg kg^-1 body weight at 12 weeks of age). Vitamin C (10, 50, 100 mg kg^-1 body weight) was administered orally for a period of four weeks to normal and diabetic male Wistar rats. In some experiments vitamin C was given either before or after the induction of diabetes mellitus. Glucose tolerance test (GTT) was performed on fasted normal, diabetic and vitamin C-treated rats at the end of the experimental period. Blood sugar level and weight were also recorded on a weekly basis for each rat in different groups. Vitamin C significantly (p<0.05) reduced blood glucose level and decreased weight gain in experimental diabetes mellitus at all doses when compared to untreated rats. This beneficial effect of vitamin C on the hyperglycemia of diabetic rats was dose-dependent. Moreover, vitamin C also improved GTT in diabetic rats compared to untreated diabetic rats. In conclusion, vitamin C may play a role in insulin metabolism and thus be a useful adjuvant therapy in diabetes mellitus.