Objectives: To study vitamin B-12 concentrations in patients with type 2 diabetes with and without metformin use and to identify risk factors and consequences of low vitamin B-12 concentrations.Research design and methods: This study had a cross-sectional design. During eight weeks all patients with type 2 diabetes visiting the diabetic outpatient clinic of the Isala Clinics in Zwolle were approached for participation. Participation included measurement of haemoglobin, mean corpuscular volume and vitamin B-12 levels. Data on neuropathy were retrospectively searched for in the patient records. Vitamin B-12 deficiency was defined as serum B-12 concentrationsResults: In the total cohort (n=298), the overall prevalence of vitamin B-12 concentrationsConclusion: Among patients with type 2 diabetes using metformin, the prevalence of vitamin B-12 deficiency is higher than compared with patients not using metformin. However, metformin use did not predict the chance of having anaemia or neuropathy.</p
