-- Shillings test
-- Stage 1: oral vitamin B12 plus intramuscular vitamin B12
* A normal result shows at least 10% of the radiolabeled vitamin B12 in the urine over the first 24 hours.
* In patients with pernicious anemia or with deficiency due to impaired absorption, less than 10% of the radiolabeled vitamin B12 is detected.
-- Stage 2: vitamin B12 and intrinsic factor
* If this second urine collection is normal, this shows a lack of intrinsic factor production, or pernicious anemia.
* A low result on the second test implies abnormal intestinal absorption (malabsorption), which could be caused by coeliac disease, biliary disease, Whipple's disease, fish tapeworm infestation (Diphyllobothrium latum), or liver disease.
-- Stage 3: vitamin B12 and antibiotics
* This stage is useful for identifying patients with bacterial overgrowth syndrome.
-- Stage 4: vitamin B12 and pancreatic enzymes
* This stage, in which pancreatic enzymes are administered, can be useful in identifying patients with pancreatitis.