Schilling Test

Other Known Aliases – none

Definitionlaboratory test for pernicious anemia (specifically intrinisic factor deficiency) that led to vitamin B12 (cobalamin) deficiency. It involved ingesting a oral dose of radiolabeled vitamin B12 (to test oral absorption), an IM injection of vitamin B12 (to saturate liver stores), and a 24hr urine collection to see how much was absorbed and excreted. If intestinal absorption was intact (intrinsic factor present), then > 10% of the radiolabeled vitamin B12 would be in the urine.

Clinical SignificanceThis was the first and only test at the time to be able to diagnose pernicious anemia, but is now largely a test of historical interest only as better diagnostic studies have been developed.

HistoryNamed after Robert F. Schilling (1919-2014) an American physician and researcher who received his medical doctorate from the University of Wisconisn-Madison in 1943. Immediately after graduation, he joined the Pacific Front as a physician in the 3d Marine Division. After the war, he completed postgraduate training at Harvard before returning to Wisconsin to practice hematology. He studied extensively on the metabolism of vitamin B12 and the urinary excretion of radiolabeled vitamin B12 in pernicious anemia and in 1953, published a paper entitled “The effect of gastric juice on the urinary excretion of radioactivity after the oral administration of radioactive vitamin B12”, which would go on to be called the “Schilling Test”.


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  5. Up To Date. www.uptodate.com
  6. Schilling RF. Intrinsic factor studies. 2. The effect of gastric juice on the urinary excretion of radioactivity after the oral administration of radioactive vitamin B12. J Clin Lab Med. 1953;42;860-866
  7. Schilling Test. Stat Pearls. 2018. https://www.ncbi.nlm.nih.gov/books/NBK507784/

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