QJM Advance Access published online on November 5, 2008
QJM, doi:10.1093/qjmed/hcn138
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An update on cobalamin deficiency in adults
From the 1The Laboratory of General and Specialized Biochemistry, Hôpitaux Universitaires de Strasbourg, 2Department of Biochemistry, Faculty of Medicine, 4 rue Kirschleger, 67000 Strasbourg and 3Department of Internal Medicine, Diabetes and Metabolic Diseases, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
Address correspondence to Prof. E. Andrès, Service de Médecine Interne, Diabète et Maladies Métaboliques, Clinique Médicale B, Hôpital Civil – Hôpitaux Universitaires de Strasbourg, 1 porte de l’Hôpital, 67091 Strasbourg Cedex, France. email: emmanuel.andres{at}chru-strasbourg.fr
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Abstract |
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Cobalamin (vitamin B12) deficiency is particularly common in the elderly (>65 years of age), but is often unrecognized because of its subtle clinical manifestations; although they can be potentially serious, particularly from a neuropsychiatric and hematological perspective. In the general population, the main causes of cobalamin deficiency are pernicious anemia and food-cobalamin malabsorption. Food-cobalamin malabsorption syndrome, which has only recently been identified, is a disorder characterized by the inability to release cobalamin from food or its binding proteins. This syndrome is usually caused by atrophic gastritis, related or unrelated to Helicobacter pylori infection, and long-term ingestion of antacids and biguanides. Besides these syndromes, mutations in genes encoding endocytic receptors involved in the ileal absorption and cellular uptake of cobalamin have been recently uncovered and explain, at least in part, the hereditary component of megaloblastic anemia. Management of cobalamin deficiency with cobalamin injections is currently well codified, but new routes of cobalamin administration (oral and nasal) are being studied, especially oral cobalamin therapy for food-cobalamin malabsorption.