Total Iron Binding Capacity
The maximum amount of iron the blood's transferrin could carry.
| Typical reference range | 250–425 ug/dL |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
TIBC indirectly measures transferrin, the iron transport protein made by the liver. When iron stores fall, the liver produces more transferrin, so TIBC rises.
Why it matters
TIBC helps distinguish iron deficiency (high TIBC) from anemia of inflammation (low or normal TIBC) and iron overload.
What a high result can mean
High TIBC suggests iron deficiency; it also rises in pregnancy and with oral contraceptives or estrogen therapy.
What a low result can mean
Low TIBC occurs with inflammation, chronic disease, malnutrition, liver disease, nephrotic syndrome and iron overload.
What affects the result
Estrogen raises TIBC. Interpret with serum iron, transferrin saturation and ferritin.
Units and conversion
Usually reported in ug/dL.
- From umol/L: multiply by 5.585 to get ug/dL
Also called on lab reports
TIBC, Iron Binding Capacity, Iron Bind.Cap.(TIBC), Iron Binding Capacity, Total
Related tests: Iron Status
This page is educational and does not replace advice from a healthcare professional.