Clinical aspects of cobalamin deficiency in elderly patients. Epidemiology, causes, clinical manifestations, and treatment with special focus on oral cobalamin therapy

The aim of this work was to review the literature concerning cobalamin deficiency in elderly patients. Articles were identified through searches of PubMed-MEDLINE (January 1990 to June 2006), restricted to: English and French language, human subjects, elderly patients (> 65 years), clinical trial, review and guidelines. Additional unpublished data from our cohort with cobalamin deficiency at the University Hospital of Strasbourg, France, were also considered. All of the papers and abstracts were reviewed by at least two senior researchers who selected the data used in the study. In elderly people, the main causes of cobalamin deficiency are pernicious anemia and food-cobalamin malabsorption. The recently identified food-cobalamin malabsorption syndrome is a disorder characterized by the inability to release cobalamin from food or from its binding proteins. This syndrome is usually the consequence of atrophic gastritis, related or not to Helicobacter pylori infection, and of the long-term ingestion of antacids and biguanides (in around 60% of the patients). Management of cobalamin deficiency has been well established with the use of cobalamin injections. However, new routes of cobalamin administration (oral and nasal) are currently being developed, especially the use of oral cobalamin therapy to treat food-cobalamin malabsorption.