Pyridoxal-5-phosphate (PLP) is the bioactive derivative of vitamin B6, functioning as a coenzyme in over 150 metabolic pathways. Insufficient PLP levels could be associated with the onset and progression of diabetes. This study aimed to assess the effects of pyridoxine adjuvant treatment on blood glucose levels in patients with type 2 diabetes mellitus (T2DM). This interventional, randomized, open-label study was conducted in the Mesan Governorate, with participants from the Mesan Center for Diabetes and Endocrinology as the study population. This study included patients newly diagnosed with T2DM. Patients were randomized into three groups: Group 1, the control group, treated with non-pharmacological therapy (lifestyle modification) (n=20); Group 2, treated with Metformin 500 mg/day in addition to non-pharmacological therapy (lifestyle modification) (n=20). Group 3 was treated with Metformin 500 mg/day plus vitamin B6 300 mg/day in addition to non-pharmacological therapy (lifestyle modification) (n=68). The findings revealed a considerably favorable impact of pyridoxine adjuvant treatment with Metformin on blood glucose levels and other study variables. Compared to the patients in the control group G1, the reductions in fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) were statistically significant in groups G2 and G3 after a 4-week treatment period. Similar results were observed for fasting serum insulin and homeostasis model assessment of insulin resistance (HOMA-IR) levels, with a significant decrease in groups G2 and G3 (p<0.05). Furthermore, the reductions in indoleamine 2,3-dioxygenase levels were also significantly higher in groups G2 and G3 at the end of the 4-week treatment period (-14.48% vs -21.16%) (p<0.05). Adding pyridoxine adjuvant therapy to Metformin treatment could effectively improve the blood glucose levels of patients with T2DM.