Iron status may be evaluated by ordering one or more tests to determine the amount of iron in the blood, the capacity of the blood to transport iron, and the amount of iron in storage. These tests may also help differentiate various causes of anemia.
Testing may include:
- TIBC (Total Iron- Binding Capacity) – measures all of the proteins in the blood that are available to bind with iron, including transferrin. Since transferrin is the primary iron-binding protein, the TIBC test is a good indirect measurement of transferrin. The body produces transferrin in relationship to the need for iron. When iron stores are low, transferrin levels increase and vice versa. In healthy people, about one-third of the binding sites on transferrin are used to transport iron.
- Total Iron – measures the level of iron in the blood.
- Transferrin Saturation – a calculation that is done with the iron test result and TIBC or UIBC. It represents the percentage of the transferrin that is saturated with iron.
- Unbound IBC – Calculation
These tests are often ordered together, and the results of each can help the doctor to determine the cause of iron deficiency and/or overload.