Serum level of Vitamin B12 and its relation to dose and duration of metformin consumption in type 2 diabetic patients

Type 2 diabetes is the most common metabolic disorder with progressive incidence .Metformin is the first choice treatment in type 2 diabetes. There are evidences that chronic of metformin consumption results in vitamin B12 deficiency, therefore we aimed to evaluate vitamin B12 levels in diabetic patients with and without metformin usage.
Overall,90 type 2 diabetic patients were selected. A questionnaire containing personal information and duration of diabetes and drug information was completed.Laboratory tests including CBC, FBS, HbA1C and vitamin B12 levels were measured. Serum vitamin B 12 below 200 pg / ml was considered as low. Patients divided into two groups with and without metformin taking and all variables compared between these two groups.
Mean age of patients was 52.5 ± 5.72 years .76, patients were consumed metformin and 14 patients didn’t take it. The mean duration of metformin using was 4.95 ± 4.57 years. The prevalence of vitamin B12 deficiency in all patients was 73.3%. Vitamin B12 level in metformin users was 159.7±132.5 pg/ml and in non - metformin users was125.4±116.2 (p=0.79). There was no significant difference between two groups regarding to B12 level and MCV. There was not any significant difference in dosage (p=0.80) and duration (p=0.63) of metformin treatment between patients with and without B12 deficiency.
Also there was no statistically significant difference in other parameters in B12 deficient patients and others.
Vitamin B12 deficiency was common in our diabetic patients but there was no relation between metformin consumption and serum vitamin B12 concentration.