Blood Iron, Transferrin and Ferritin Tests and Total Iron Binding Capacity (TIBC)
Why is this test done? | These tests are useful to differentiate the various types of anemias. They help to establish iron stores. Measuring these parameters is a good way to assess a person's nutritional status. |
How to prepare: |
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Target Values: |
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Associated Tests: | Usually, iron, ferritin and transferrin tests and total iron binding capacity are done in combination with hemoglobin tests and red blood cell count (hematocrit). |
General Information
Iron plays several important functions in the body. It is involved in the formation and functioning of hemoglobin found in red blood cells. Most iron is found in hemoglobin, the rest is stored as ferritin. Iron needs a protein, called transferrin, to travel in the blood. Blood iron levels represent the balance between dietary intake and iron losses (menses, loss in stools, etc.). Ferritin levels are useful to assess body iron stores. Iron binding capacity is calculated from blood transferrin levels and is expressed as a percentage. It is used to distinguish the various types of anemia.
The four most frequent iron-related tests are::
- serum iron - measures iron levels in serum; represents iron that is almost completely bound to transferrin;
- transferrin - measures levels of the iron carrier;
- total iron binding capacity (TIBC) - measures the transferrin capacity to bind iron;
- serum ferritin - measures the body's ability to store iron.
What does an abnormal test result mean?
If the result is too high
- Iron
There may be excessive amounts of iron in the blood, a condition called hemosiderosis or hemochromatosis. Liver problems can also explain elevated results. - Ferritin
Ferritin levels may be too high because iron levels are too high. Liver cirrhosis, hyperthyroidism, non iron deficiency anemia and inflammatory states can explain elevated results. - Transferrin and total iron binding capacity
This indicates iron deficiency anemia or hemochromatosis.
- Iron
Indicates iron deficiency anemia. Low iron levels can also be seen in people with poor dietary iron absorption or poor diet. Low iron levels are often associated with certain chronic diseases. - Ferritin
Also indicates iron deficiency anemia. - Transferrin and total iron binding capacity
In some cases, indicates inflammatory disease or low blood proteins.
Factors that can affect the result of the test
Pregnancy can affect results, usually making them lower. Recent blood transfusion increases the amount of blood iron. Among drugs, oral contraceptives (the "pill") increase blood iron levels and iron binding capacity.
What you need to know before the test
Before going for blood tests, a procedure or other exam, it is best to always bring a list of all the drugs you take (prescription, OTC and natural health products). Unless told otherwise, you should take your medication as usual on the day of the test. When in doubt, ask your pharmacist for more information.
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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.