TIBC
Total iron-binding capacity (TIBC) measures the maximum amount of iron that transferrin proteins in the blood can carry. It is an indirect measure of transferrin concentration. When iron stores are low, the liver produces more transferrin to capture more iron — so TIBC rises. When iron stores are adequate, TIBC decreases.
Why it matters: TIBC moves opposite to iron stores — high TIBC with low ferritin is the pattern of iron deficiency, while low TIBC with high ferritin is associated with iron overload or chronic inflammation. With serum iron, it is used to calculate transferrin saturation, a useful iron-panel metric.
May increase with:
May decrease with:
What is TIBC?
Total iron-binding capacity (TIBC) measures the maximum amount of iron that transferrin proteins in the blood can carry. It is an indirect measure of transferrin concentration. When iron stores are low, the liver produces more transferrin to capture more iron — so TIBC rises. When iron stores are adequate, TIBC decreases.
What might a high or low TIBC mean?
TIBC moves opposite to iron stores — high TIBC with low ferritin is the pattern of iron deficiency, while low TIBC with high ferritin is associated with iron overload or chronic inflammation. With serum iron, it is used to calculate transferrin saturation, a useful iron-panel metric.
What is the typical reference range for TIBC?
The general-population reference range shown here is 45 – 72 umol/L. Reference ranges describe the general population and are not a personal target — discuss your results with your physician.
What can affect TIBC?
It may be higher with: Iron deficiency (compensatory increase in transferrin), Pregnancy (increased iron demand), Oral contraceptive use, Hepatitis (acute). It may be lower with: Iron overload (hemochromatosis), Chronic inflammation, Chronic liver disease (reduced transferrin synthesis), Malnutrition, Nephrotic syndrome (urinary protein loss).