Emmanuel Andrès, MD, Professor of Internal Medicine, Strasbourg University; Head of the Department of Internal Medicine, Diabetes and Metabolic Diseases, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
Mustapha Mecili, MD, Clinical Specialist, Department of Internal Medicine, Diabetes and Metabolic Diseases, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
Helen Fothergill, MD, Clinical Specialist, Department of Internal Medicine, Diabetes and Metabolic Diseases, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
Thomas Vogel, MD, Clinical Specialist, Department of Internal Medicine and Geriatrics, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.
Laure Federici, MD,Clinical Specialist, Department of Medicine, Hôpitaux de Colmar, Colmar, France.
Jacques Zimmer, MD PhD, Clinical Researcher, Laboratoire d’Immunogénétique-Allergologie, Centre de Recherche Public de la Santé (CRP-Santé) de Luxembourg, Luxembourg.

Cobalamin (vitamin B12) deficiency is particularly common in among older adults, although it is frequently undiagnosed as the clinical presentations may be subtle. However, serious complications do occur, in particular neuropsychiatric and hematological disorders. In older adults, the main causes of cobalamin deficiency are food-cobalamin malabsorption (50–60%) and pernicious anemia (30–40%). Food-cobalamin malabsorption syndrome is a disorder characterized by the inability to release cobalamin from food or its binding proteins. This syndrome is frequently associated with atrophic gastritis, which may be a result of Helicobacter pylori infection, and long-term ingestion of antacids and biguanides. The management of cobalamin deficiency with cobalamin injections is currently well documented, however new routes of cobalamin administration (including via oral and nasal passages) are being studied. Oral cobalamin therapy is of particular interest in the management of food-cobalamin malabsorption syndrome.
Key words: cobalamin, vitamin B12, cobalamin deficiency, food-cobalamin malabsorption, oral cobalamin therapy.