Effect of Vitamin C on Blood Glucose Levels, Glycosylated Hemoglobin, and Serum Lipid Profile in Patients with Type 2 Diabetes Mellitus: A Prospective Study

Background: Vitamin C reduces oxidative stress as well as prevents nonenzymatic glycosylation of proteins because of its structural similarity to glucose. This prospective study was conducted to investigate the impact of vitamin C supplementation on glycemic control and serum lipid profile in newly diagnosed patients with type 2 diabetes mellitus (T2DM). Materials and Methods: Adult patients attending the outpatient department of a tertiary care hospital, diagnosed with T2DM within the last 3 months, with fasting blood glucose (FBG) levels exceeding 126 mg/dL, were randomly assigned to either control group (n = 98) or study group (n = 102). The study group received oral vitamin C (1 g/day) in addition to metformin 500 mg twice daily, while the control group received metformin 500 mg twice daily alone. Baseline characteristics, including age, gender, and comorbidities, were recorded. The parameters FBG, postprandial blood glucose (PPBG), glycosylated hemoglobin (HbA1c), and serum lipid profile were measured at baseline and at the 12th week. Results: Both the control and study groups experienced significant reductions in FBG, PPBG, and HbA1c levels after 12 weeks. However, the study group exhibited greater improvements, with FBG decreasing by 22.42 ± 2.7 mg/dL (P < 0.05), PPBG decreasing by 33.25 ± 4.9 mg/dL (P < 0.05), and HbA1c decreasing by 1.33 ± 0.3 g% (P < 0.05). Additionally, both groups demonstrated significant improvements in serum lipid profile parameters, with the study group showing more significant improvements in high-density lipoprotein, low-density lipoprotein, triglycerides, and total cholesterol levels compared to the control group. Conclusion: Vitamin C supplementation as an adjuvant therapy with metformin for 12 weeks produces beneficial effects in T2DM patients, including improved glycemic control and significant improvement in the lipid profile.