Vitamin B12 deficiencies due to malabsorption which may be associated with the following conditions:

1. Addisonian (pernicious) anemia.
2. Gastrointestinal pathology, dysfunction, or surgery, including gluten enteropathy or sprue, small bowel bacterial overgrowth, total or partial gastrectomy.
3. Fish tapeworm infestation.
4. Malignancy of pancreas or bowel.
5. Folic acid deficiency.