Abstract

Vitamin B 12 deficiency affects 10% to 15% of people over 60 years of age and is associated with haematological, neurological and psychiatric manifestations. Prolonged use of metformin is associated with Vitamin B12 malabsorption - an effect under recognized by most clinicians who prescribe this oral anti-diabetic. It is estimated that 30% of patients on metformin have vitamin B12 malabsorption. Annual vitamin B12 dosing is recommended for all patients receiving metformin. Injectable vitamin B12 supplementation (1 mg) once a year in long-term metformin patients may be a practical and cost-effective measure.