In 1930, researcher William Castle conducted clever experiments feeding patients predigested meat and gastric juices. He deduced that a normal stomach secretes an that must bind with an "Extrinsic Factor" (the antipernicious anemia factor in food) to allow the body to absorb it. Patients with pernicious anemia, he discovered, lacked this intrinsic factor due to stomach atrophy. 3. Isolation of Vitamin B12 (1948) Pernicious anemia: MedlinePlus Medical Encyclopedia
In 1849, British physician Thomas Addison provided the first clear description of the disease, which is why it was originally known as Addisonian anemia. antipernicious anemia factor
Eating massive amounts of raw or lightly cooked liver was nauseating and difficult for patients to sustain. Scientists knew there was a specific compound in the liver curing the disease—the "antipernicious anemia factor"—but they didn't know what it was. Scientists knew there was a specific compound in