False statement regarding Schilling test is:
**Core Concept**
The Schilling test is a radiolabeled test used to assess the absorption of vitamin B12. It involves oral ingestion of radioactive vitamin B12 and subsequent measurement of urinary excretion. This test helps diagnose and differentiate between pernicious anemia, gastritis, and other causes of vitamin B12 deficiency.
**Why the Correct Answer is Right**
The Schilling test is a reliable method for evaluating the body's ability to absorb vitamin B12. The test measures the excretion of radioactive vitamin B12 in the urine over a 24-hour period. A normal result indicates that the body is absorbing vitamin B12 properly, while a low result suggests a deficiency or impaired absorption. The test involves administering radioactive vitamin B12 orally and measuring the amount excreted in the urine, which is then compared to a baseline measurement.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the Schilling test is indeed used to assess the absorption of vitamin B12, not folate.
**Option B:** This option is incorrect because the Schilling test involves radioactive vitamin B12, not radioactive folic acid.
**Option C:** This option is incorrect because the Schilling test is not used to diagnose celiac disease, although it can be used to assess malabsorption in general.
**Clinical Pearl / High-Yield Fact**
The Schilling test is a useful tool for diagnosing pernicious anemia and other causes of vitamin B12 deficiency. It is essential to note that the test is not 100% sensitive and specific, and results should be interpreted in conjunction with clinical findings and other laboratory tests.
**Correct Answer:** B.