Vitamin B12 Deficiency and Foot Ulcers in Type 2 Diabetes Mellitus: A Case-Control Study

Objective: To assess the association between vitamin B-12 deficiency and the development of diabetic foot ulcers (DFU) in type 2 diabetes mellitus (T2DM). Methods: This is a case-control study that enrolled 323 Saudi adults with T2DM randomly selected from the Jazan Diabetes & Endocrine Center, Saudi Arabia from January 1, 2019, to July 31, 2019. The sample included 108 newly diagnosed cases with DFU and 215 control participants with T2DM unaffected by and free of foot ulcers (1:2 ratio). Logistic regression analysis was performed to determine the DFU predictors and to examine the association of DFU and vitamin B-12 deficiency. Results: The highest DFU rates were found among the male participants and the participants older than 45 years. Neuropathy, vasculopathy, vitamin B-12 deficiency, poor glycemic control, poor feet self-care, Charcot foot, physical inactivity, and spending long time standing at work were significantly associated with DFU, and all except physical inactivity and spending long time standing at work were independent predictors of DFU. After adjustment for the covariates, vitamin B-12 deficiency was significantly associated with DFU (odds ratio 3.1), indicating that the patients with T2DM and vitamin B-12 deficiency had a three times higher risk of developing DFU than those with normal vitamin B-12 levels. Conclusion: Vitamin B-12 deficiency had a significant association with DFU among the Saudi participants with T2DM. Establishing the causality and clarifying the biological role of vitamin B-12 deficiency in DFU is important aims for future studies.