Transferrin saturation
The percentage of the blood's iron carrier that is actually loaded with iron.
What it is
Transferrin saturation divides serum iron by total capacity. Low saturation suggests iron deficiency; persistently high saturation is the screening signal for iron overload.
Why it matters
It is the key number for suspected iron overload (haemochromatosis) and part of the standard picture for deficiency; a single high reading is usually repeated fasted.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
How it affects the body
It reflects how much usable iron is in transit to the marrow and tissues.
For athletes
Low saturation with normal ferritin can still limit performance; recheck fasted before supplementing, as iron behaves badly when taken blind.
Related tests
No published panels currently list this marker.