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.
A decreased vitamin B12 level and/or increased methylmalonic acid and homocysteine levels as well as a positive test result for intrinsic factor antibodies and/or parietal cell antibodies means that it is likely that the person tested has pernicious anemia. A negative test result does not necessarily mean that a person does not have pernicious anemia. At least 10% of those affected will not have parietal cell antibodies. Parietal cell antibodies are not as specific as intrinsic factor antibodies. About 90% of those with pernicious anemia will have parietal cell antibodies, but they may also be found in: