Long known as the âsunshine vitaminâ because the body makes it when skin is exposed to sunlight, vitamin D might now be dubbed the âsuperstar vitamin,â judging by the amount of attention it has garnered of late from researchers and the general public.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test. Vitamin B12 deficiency can be caused by many factors, one of which is pernicious anemia, a condition resulting in deficient production of intrinsic factor in the parietal cells of the stomach. Intrinsic factor is a protein that is needed to assist in the absorption of vitamin B12 into the small intestine.
Intrinsic factor antibodies are proteins produced by the immune system that are associated with pernicious anemia. This test detects intrinsic factor antibody (IF antibody) circulating in blood.Intrinsic factor is a protein produced by a type of specialized cells that line the stomach wall known as parietal cells. During digestion, stomach acids release vitamin B12 from food and bind to intrinsic factor to form a complex. Intrinsic factor blocking antibody (type 1), which is more specific for pernicious anemia and is the one that is usually tested. 2  Intrinsic factor binding antibody (type 2), which interferes with the uptake of the vitamin B12-instrinsic factor complex.