Effect of a combination of gliptin and metformin on serum vitamin B12, folic acid, and ferritin levels

OBJECTIVE: The primary objective of this study was to explore the impact of metformin and metformin/gliptin combination therapy on the serum concentrations of vitamin B12, ferritin, and folic acid in individuals diagnosed with type 2 diabetes. METHODS: This study included 118 patients, classified into two groups: 59 patients using only metformin and 59 patients using a combination of metformin/gliptin. Among the latter group, 35 patients used vildagliptin/metformin, and 24 used sitagliptin/metformin. The study recorded the demographic data such as the age and gender of the patients, as well as their initial and 1-year follow-up blood parameters. RESULTS: Folic acid decreased significantly in the metformin group but not in the metformin/gliptin group. Vitamin B12 and ferritin decreased significantly in both groups. The decrease in vitamin B12 and ferritin was not significantly different between the two groups. The decrease in fasting plasma glucose was more significant in the metformin/gliptin group than in the metformin group. CONCLUSION: After 1 year, both groups taking metformin and metformin/gliptin showed low serum ferritin and vitamin B12 levels. Therefore, vitamin B12 levels in patients using these drugs should be closely monitored. Ferritin levels can be used to indicate whether glycemic control has been achieved.