Folic acid and vitamin B12 supplementation in subjects with type 2 diabetes mellitus: A multi-arm randomized controlled clinical trial.

OBJECTIVE This study was conducted to investigate and compare the effects of add-on folic acid and vitamin B12 supplementation on glycaemic control, insulin resistance and serum lipid profile in subjects with type 2 diabetes mellitus. STUDY DESIGN & INTERVENTION This study was a randomized, multi-arm, open-label clinical trial. 80 patients with type 2 diabetes and on stable oral antidiabetics were enrolled and 20 patients each were randomly allocated to one of the four groups - Group A: add-on Folic acid (5 mg/day); Group B: add-on Methylcobalamin (500 mcg/day); Group C: add-on Folic acid (5 mg/day) + Methylcobalamin (500 mcg/day) and Group D: Standard oral anti-diabetic drugs. The patients were followed up after 8 weeks. RESULTS HbA1c improved significantly in Groups B and C [median changes from baseline - 1.2 % (- 13 mmol/mol) and - 1.5 % (- 16 mmol/mol) respectively, p values 0.04 and 0.02 respectively] compared to Group D. Groups B and C also showed significant improvements in plasma insulin, insulin resistance and serum adiponectin compared to Group D. Serum homocysteine declined significantly in all three groups with add-on supplementation compared to standard treatment. No improvement in the lipid profile was noted in any of the groups. CONCLUSIONS Add-on supplementation with vitamin B12 improved glycaemic control and insulin resistance in patients with type 2 diabetes mellitus.