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.
Why the Test is Performed. This test is most often done when other blood test tests suggest a condition called megaloblastic anemia. Pernicious anemia is a form of megaloblastic anemia caused by poor vitamin B12 absorption. This can occur when the stomach makes less of the substance the body needs to properly absorb vitamin B12. Your doctor may also order a vitamin B12 test if you have certain nervous system symptoms.