TIBC, UIBC and Transferrin
Note: this site is for informational purposes only. To view test results or book a test, use the NHS app in England or contact your GP.
A TIBC, UIBC and transferrin test measures the blood’s capacity to bind and transport iron by assessing transferrin and related markers using a blood sample taken from a vein in the arm. It is used to evaluate iron levels and help diagnose conditions such as iron deficiency anaemia or iron overload disorders.
Why get tested?
To learn about your body’s iron stores
When to get tested?
When your doctor suspects you may have too much or too little iron in your body because of a variety of conditions
Sample required?
A blood sample taken from a vein in your arm
Test preparation needed?
You may be instructed to fast for 12 hours before the test; in this case, only water is allowed.
Common questions
TIBC or transferrin are typically used along with iron and ferritin to evaluate people suspected of having too much or too little iron stored within their body. Usually, about one third of the transferrin measured is being used to transport iron, and this is called transferrin saturation. In iron deficiency, iron is low and fewer transferrin binding sites are used. This results in a low transferrin saturation, but an increased TIBC. In iron overload, such as in haemochromatosis, iron and transferrin saturation will be high and TIBC will be low or normal.
Because transferrin is made in the liver, TIBC and transferrin will also be low with liver disease.
TIBC (or transferrin) measurements may be requested when it appears that you have too much or too little iron in your system. If you have anaemia, especially if the red cells are small and pale (microcytic and hypochromic), this may be due to iron deficiency and iron tests are usually performed. If your doctor suspects you may have too much iron, or if you have a family history of haemochromatosis, iron and TIBC (or transferrin or UIBC) may be used to see if further testing is needed.
High TIBC or transferrin, or low transferrin saturation, usually indicates iron deficiency. A low TIBC or transferrin, or high transferrin saturation may occur if you have haemochromatosis (too much stored iron). Other causes of abnormal results include anaemia caused by infections and chronic diseases, malnutrition, cirrhosis, or nephrotic syndrome (a kidney disease that causes loss of protein in urine).
A summary of the changes in iron tests seen in various diseases of iron status is shown in the table below.
| Disease | Iron | TIBC/Transferrin | UIBC | % Transferrin Saturation | Ferritin |
| Iron Deficiency | Low | High | High | Low | Low |
| Haemochromatosis | High | Low | Low | High | High |
| Chronic Illness | Low | Low | Low/Normal | Low | Normal/High |
| Iron Poisoning | High | Normal | Low | High | Normal |
Taking the oral contraceptive pill can result in a higher TIBC result.
Taking chloramphenicol can decrease TIBC levels. Some laboratories routinely only use studies of the red cells (FBC) and ferritin to investigate anaemia and monitor treatment.
Yes. Transferrin attaches to iron and then transports and releases it in your bloodstream.