Journal of Mazandaran University of Medical Sciences (Nov 2023)
The Relationship between Metformin Use and Reduced Vitamin B12 Levels in Patients with Type 2 Diabetes
Abstract
Background and purpose: Given the inevitable use of metformin in treatment, the management and possible elevation of cobalamin levels by metformin use should be addressed. However, the reduction in vitamin B12 levels caused by metformin has been mentioned in many studies and books, but there is no suggestion for the concomitant use of vitamin B12 with metformin. This study was conducted with the aim of assessing the association between metformin use and vitamin B12 depletion in type 2 patients Materials and methods: In this descriptive cross-sectional study, 96 people were randomly selected. Two clinic patients referred to Tankab Hospitals and Imam Sajjad (AS) Ramsar Hospital internal clinic with normal CBC from the beginningwere included in this study. Information was recorded in patient records through paraclinics and interviews. 5 ml of venous blood samples was drawn these patients who had been taking metformin for at least 6 months to determine hemoglobin levels, red blood cell indices including MCV, and vitamin B12 levels. CBC and B12 plasma level were taken.t-tests and analysis of variance, Mann-Whitney and Kruskal-Wallis tests, chi-square tests and logistic regression were used. The software used in this study is IBM-SPSS V.20, and the significance level of the tests is considered to be less than 5%. Results: In this study, 96 patients were examined. The differences in vitamin B12 levels in diabetic patients taking metformin were borderline significant depending on age (P=0.063). The vitamin B12 level was significantly higher in men than in female patients (P=0.023). There were no statistically significant differences in vitamin B12 levels depending on BMI, Hb level, underlying disease and use of other hypoglycaemic medication (P>0.05). The frequency of vitamin B12 level was significantly lower in diabetic patients taking metformin with normal MCV than in patients with MCV (P=0.012). The frequency of vitamin B12 level was highestin diabetic patients taking 2000 mg metformin per day (13.3%) and lowest in patients taking 500 mg per day, and this difference was statistically significant (P=0.013). Conclusion: The results show that metformin causes a decrease in vitamin B12 levels in diabetics who take it. Due to the high prevalence of vitamin B12 deficiency caused by metformin and its relationship with dose and duration of use, patients ' serum levels of vitamin B12 should be monitored regularly and, in case of deficiency or symptoms of deficiency, patients should take vitamin B12 supplements to improve the quality of treatment and prevent complications caused by diabetes and metformin.
