Update of Food-Cobalamin Malabsorption and Oral Cobalamin Therapy

Abstract

Cobalamin (vitamin B12) deficiency is particularly common in the elderly (>65 years of age), but is often unrecognized because its clinical manifestations are subtle; however, they are also potentially serious, particularly from a neuropsychiatric and hematological perspectives. 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. 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.

Pseudothrombotic Microangiopathy as a Rare Presentation of Cobalamin Deficiency

“…Standard treatment consists of intramuscular cobalamin replacement once monthly for life, preceded by an initial intensive regimen (1mg weekly for eight weeks or 1mg daily for seven days followed by once weekly for four weeks); an equally effective alternative for maintenance therapy involves higher doses of oral cobalamin (1-2mg daily) in compliant patients [ 5 , 16 ].…”

“…The major causes of cobalamin deficiency are malabsorption (secondary to pernicious anemia, reduced gastric acidity, gastrointestinal pathology, or surgery) and inadequate dietary intake associated with vegetarianism [5,6]. Other etiologies include hereditary metabolic diseases, fish tapeworm infection, and exposition to drugs that interfere with cobalamin absorption or stability [7,8].…”

“…Epidemiological studies show a 20% prevalence of cobalamin deficiency in the general population of industrialized countries. In elderly and/or institutionalized subjects, the prevalence may be higher, ranging from 12% to 30-40% [ 5 ]. However, due to the lack of a consensual definition, these numbers vary according to the threshold of normality used and, thus, real prevalence is difficult to assess.…”