Efficacy of oral cobalamin (vitamin B12) therapy.

IMPORTANCE OF THE FIELD: Cobalamin (vitamin B12) deficiency is particularly common in the elderly (> 15%). Management of cobalamin deficiency with cobalamin injections is well codified at present, but new routes of cobalamin administration (oral and nasal) are being studied, especially oral cobalamin therapy for food-cobalamin malabsorption. AREAS COVERED IN THIS REVIEW: The objective of this review is to evaluate the efficacy of oral cobalamin treatment in elderly patients. To reach this objective, PubMed data were systematically searched for English and French articles published from January 1990 to July 2008. Data from our research group on cobalamin deficiency (Groupe d'Etude des CAREnce vitamine B12 - CARE B12) were also analyzed. WHAT THE READER WILL GAIN: Three prospective randomized studies, a systematic review by the Cochrane group and five prospective cohort studies were found and provide evidence that oral cobalamin treatment may adequately treat cobalamin deficiency. The efficacy was particularly highlighted when looking at the marked improvement in serum vitamin B12 levels and hematological parameters, for example hemoglobin level, mean erythrocyte cell volume and reticulocyte count. The effect of oral cobalamin treatment in patients presenting with severe neurological manifestations has not yet been adequately documented. Oral cobalamin treatment avoids the discomfort, inconvenience and cost of monthly injections. TAKE HOME MESSAGE: Our experience and the present analysis support the use of oral cobalamin therapy in clinical practice.