Clinical Significance
The serum iron test is used to measure the amount of iron that is in transit in the body – the iron that is bound to transferrin in the blood. Along with other tests, it is used to help detect and diagnose iron deficiency or iron overload. Testing may also be used to help differentiate various causes of anemia.
The amount of iron present in the blood will vary throughout the day and from day to day. For this reason, serum iron is almost always measured with other iron tests, including ferritin, transferrin, and calculated total iron-binding capacity (TIBC) and transferrin saturation.
Specimen
Serum
Stability
Refrigerated (preferred) : 7 days
Frozen : 180 days
Reference Range
33- 193 µg/dL
Interpretation
| Disease | Iron | TIBC/Transferrin | UIBC | %Transferrin Saturation | Ferritin |
|---|---|---|---|---|---|
| Iron Deficiency | Low | High | High | Low | Low |
| Hemochromatosis/Hemosiderosis | High | Low | Low | High | High |
| Chronic Illness | Low | Low/Normal | Low/Normal | Low/Normal | High/Normal |
| Hemolytic Anemia | High | Normal/Low | Low/Normal | High | High |
| Sideroblastic Anemia | Normal/High | Normal/Low | Low/Normal | High | High |
| Iron Poisoning | High | Normal | Low | High | Normal |
Limitation
Recent consumption of iron-rich foods or iron supplements can affect test results, as can recent blood transfusions.