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 and inversely correlates with iron status — when iron stores are depleted, the liver produces more transferrin to capture available iron, raising TIBC.
TIBC is most useful when paired with serum iron to calculate transferrin saturation (serum iron / TIBC x 100). High TIBC with low serum iron is a classic pattern of iron deficiency. Low TIBC may indicate chronic inflammation, liver disease, or iron overload.
TIBC is less affected by daily fluctuations than serum iron, making it a more stable component of the iron panel.
What It Measures
Total capacity of blood transferrin proteins to bind and transport iron, reflecting transferrin production by the liver.
Reference Ranges
| Status | Range (mcg/dL) |
|---|---|
| Optimal | 250–370 mcg/dL |
| Normal | 250–400 mcg/dL |
| Borderline | 400–450 mcg/dL |
| Out of Range | > 450 mcg/dL or < 200 mcg/dL |
How GATOR Tracks This
Lab Providers
Related Clinical Ratios
Related Biomarkers
This content is for informational purposes only and does not constitute medical advice. Reference ranges may vary by laboratory and individual factors. Consult a qualified healthcare provider for interpretation of your results and treatment decisions.
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