Pernicious Anemia and Malabsorption, with Spinal Cord Degeneration Developing During Vitamin B_12 Treatment

Abstract

A 44-year-old farmer with pernicious anemia and occult gastrointestinal bleeding responded incompletely to the regular administration of vitamin B12 and Fe. He developed typical, progressive combined systems disease during the course of intramuscular vitamin B12 therapy. After amebic colitis was diagnosed and treated, his blood loss was arrested. A tentative diagnosis of non-tropical sprue was based on malabsorption of fat and carbohydrate, as well as of vitamin B12 and intrinsic factor. After the patient omitted gluten from his diet, the blood counts became normal and no progression of neurologic disease. However, no objective improvement occurred in absorption or intestinal morphology. Possible mechanisms are proposed to explain the development of combined systems disease in the presence of active vitamin B12. No abnormality of vitamin B12 binding to serum proteins could be demonstrated. Abnormal B12 transport or utilization, and malabsorption of another essential nutrient remain possible explanations.