Folate and vitamin B12 deficiency and hyperhomocysteinemia promote oxidative stress in adult type 2 diabetes

Objective: The purpose of this study was to examine the status of folate and vitamin B12 (B12) in relation to serum homocysteine (HCY) and oxidative stress indices in patients with type 2 diabetes (T2DM). Methods: This case-control study involved 100 Omani adults (50 patients newly diagnosed with T2DM and 50 age- and gender-matched healthy controls). Several parameters were investigated, including dietary intake and biochemical assessments of folate, B12, HCY, oxidative stress markers (glutathione and total antioxidant status), and antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). Results: Low serum levels of folate, B12, and hyperhomocysteinemia were prevalent in patients with T2DM compared with controls. Oxidative stress was evident in patients with T2DM as indicated by low serum levels of glutathione, total antioxidant status, and impaired antioxidant enzymatic activities (superoxide dismutase, glutathione peroxidase, and catalase). Conclusion: The low intake of folate and B12 is associated with low serum levels of these two nutrients and hyperhomocysteinemia in Omani adults with T2DM.