The Schilling test is a test that evaluates the absorption of vitamin B12 by the body. The Schilling test is performed in the case of a deficiency of this vitamin in the body to determine the causes of this condition. What is the Schilling test? How to prepare for the test? How to interpret its results?

Contents:

  1. Schilling test - indications for the test
  2. Schilling test - how to prepare for the test?
  3. Schilling test - what is the test?
  4. Schilling test - standard. Interpretation of test results
  5. Extended Schilling test - what is it?
  6. Schilling test - next stages of the test

Schilling testtostudyto assess the absorption of vitamin B12 (cobalamin, the "red vitamin") from the gastrointestinal tract by measuring its excretion with urine.

Schilling test - indications for the test

The indication for the test is vitamin B12 deficiency, which is manifested, among others, by burning and inflammation of the tongue, unusual sensations (including tingling and numbness), memory impairment, pale skin and mucous membranes, and general weakness of the body.

Schilling test - how to prepare for the test?

The patient should be on an empty stomach and have an empty bladder. In addition, he should inform the doctor about all the recently taken medications. This is very important because some antibiotics, cancer drugs (e.g. methotrexate), as well as metformin (a drug used by diabetics) and aspirin (acetylsalicylic acid) affect vitamin B12 levels with false-negative results.

The absorption of colchicine (used in acute gout attacks) and p-aminosalicylic acid (an anti-tuberculosis drug) may lead to the malabsorption of vitamin B12, and hence - falsification of test results. Also, folic acid used in high doses over a long period of time reduces the amount of vitamin B12 in the blood. In addition, even consuming high doses of alcohol for more than 2 weeks may lead to false results.

Schilling test - what is the test?

The patient swallows a radiolabeled 1 microgram tabletvitamin B12 cob alt. After 1-2 hours, an intramuscular injection is given containing 1,000 micrograms of vitamin B12, which is no longer cob alt-labeled.

The patient then performs a 24-hour urine collection. After 24 hours, the urine is transferred to the laboratory, where the radioactivity is measured. This allows an assessment of the amount of vitamin B12 excreted in the urine.

Menstruating women should not urinate 3 days before and 3 days after their period.

Schilling test - standard. Interpretation of test results

After the test, a he althy person expels 10 percent. and more (usually up to 40%) of the administered dose of vitamin B12 in the daily urine collection

If the patient urinated<7 proc., może to oznaczać nieprawidłowe wchłanianie kobalaminy w przewodzie pokarmowym, spowodowane takimi chorobami jak:

  • pernicious anemia
  • liver disease
  • hypothyroidism
  • celiakia

However, it should be taken into account that these values ​​may differ depending on the laboratory where the test is performed.

Extended Schilling test - what is it?

If the test result is incorrect, 3-7 days after the end of the test, the next steps are carried out to determine the causes of vitamin B12 deficiency.

The purpose of the second step of the Schilling test is to determine whether the cause of the cobalamin deficiency is Addison-Biermer disease (pernicious anemia), which results from the destruction of an intrinsic factor (Castle's factor, which normally binds to vitamin B12, allowing it to absorption - editor's note).

The patient is re-administered orally with a dose of vitamin B12 labeled with radioactive cob alt, but this time with an intrinsic factor. Then the patient again conducts the 24-hour urine collection. If the cause of the vitamin B12 deficiency is Addison-Biermer disease, its absorption is normal and the patient excretes 10% of the vitamin. and more of the administered dose. Otherwise, the doctor may order another stage of the examination.

Currently, in order to confirm / exclude pernicious anemia, determination of antibodies against intrinsic factor is significantly more frequent than the Schilling test.

Schilling test - next stages of the test?

The third stage of the study allows us to answer the question whether the abnormal growth of bacteria is responsible for the malabsorption of vitamin B12. Your doctor will prescribe you antibiotics, which you must take for 2 weeks. After this period, he performs a 24-hour urine collection again. If the test is positive, then bacteria was the cause of the malabsorption of the vitamin. If negative, the doctor will order the last stage of the Schilling test.

The final stagetests can determine whether the cause of malabsorption of vitamin B12 is the abnormal functioning of the pancreas. To this end, the doctor orders the patient to take pancreatic enzymes for 3 days. After this time, the patient performs a 24-hour urine collection. Correct result indicates pancreatic diseases.

Read also:

  • Symptoms and causes of vitamin B12 deficiency
About the authorMonika Majewska A journalist specializing in he alth issues, especially in the areas of medicine, he alth protection and he althy eating. Author of news, guides, interviews with experts and reports. Participant of the largest Polish National Medical Conference "Polish woman in Europe", organized by the "Journalists for He alth" Association, as well as specialist workshops and seminars for journalists organized by the Association.

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Research