Low Plasma Ascorbate Levels in Type 2 Diabetic Patients With Adequate Dietary Vitamin C.

Dietary intake of antioxidative vitamin C plays a protective role in the prevention of oxidative damage in diabetics, demanding increased requirement of vitamin C. Hyperglycemia results in impaired uptake of vitamin C in the cell. The present study was conducted to compare the plasma ascorbate levels in type 2 diabetic patients and controls consuming adequate dietary vitamin C.  Fifty consented type 2 diabetes mellitus (T2DM) patients who were on treatment with oral hypoglycemic drugs and consuming adequate vitamin C in diet were taken in the study and 50 healthy controls equitably matched for age, gender between 40 and 70 years, and dietary intake of vitamin C were compared. Dietary intake of vitamin C was estimated by a food frequency questionnaire. Subjects consuming more than 35 mg/d of vitamin C were included in the study. Fasting blood sugar was estimated by glucose oxidase and peroxidase method and estimation of ascorbic acid was done by using 2, 4 dinitro phenyl hydrazine method.  The mean ± standard deviation levels of plasma ascorbate levels in diabetic subjects were 0.22 ± 0.12 mg/dL, which were significantly lower as compared with controls with plasma ascorbate level of 0.47 ± 0.15 mg/dL. In diabetic subjects, insignificant positive correlation was observed between these parameters with -value 0.168 and -value 0.245.  This study concludes that even with the recommended dietary intake of vitamin C low plasma ascorbate levels were found among T2DM patients, which necessitates increased demand and dietary advice to diabetic patients on consuming foods rich in vitamin C more than the recommended daily allowance.