Objective: Metformin produce low vitamin B12 levels by mechanisms related to alterations in gut absorption 1-10. The objective of this study is to evaluate if patients with metformin induced vitamin B12 deficiency have higher prevalence of vitamin D deficiency. Material and Methods: Cross sectional study. 156 patients were included. Patients were classified in three groups according to B12 levels, low, less than 200 pg/ml and borderline, 201 to 300 pg/ml or normal, more than 300 pg/ml. Vitamin D status was obtained from the records of the patients