Total iron binding capacity (TIBC) is a blood test to see if you have too much or too little iron in your blood. Iron moves through the blood attached to a protein called transferrin. This test helps your health care provider know how well that protein can carry iron in your blood.
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
You should not eat or drink for 8 hours before the test.
Certain medicines may affect the result of this test. Your provider will tell you if you need to stop taking any medicines. Do not stop any medicine before talking to your provider.
Medicines that can affect the test result include:
- Adrenocorticotropic hormone (ACTH)
- Birth control pills
- Chloramphenicol
- Fluorides
How the Test will Feel
When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing or a slight bruise. This soon goes away.
Why the Test is Performed
Your provider may recommend this test if:
- You have signs or symptoms of anemia due to low iron
- Other lab tests suggest you have anemia due to low iron levels
What Abnormal Results Mean
TIBC is usually higher than normal when the body’s iron supplies are low. This can occur with:
- Iron deficiency anemia
- Pregnancy (late)
Lower-than-normal TIBC may mean:
- Anemia due to red blood cells being destroyed too quickly (hemolytic anemia)
- Lower-than-normal level of protein in the blood (hypoproteinemia)
- Inflammation
- Liver disease, such as cirrhosis
- Malnutrition
- Decrease in red blood cells from the intestines not properly absorbing vitamin B12 (pernicious anemia)
- Sickle cell anemia