Transferrin Saturation
Transferrin Saturation %
- Sample
- Blood
- Usual units
- %
Also known as Transferrin Saturation % · TSAT · Iron Saturation · % Transferrin Saturation · % Saturation
What this test measures
Transferrin saturation is the share of transferrin's iron-binding sites currently occupied by iron, calculated from a serum iron result together with the blood's total iron-binding capacity. Because it relates iron in transit to the capacity available to carry it, a lab reads it alongside iron and ferritin to build a fuller picture of how iron is being carried through the body. It is reported as a percentage.
Reading your report
There isn’t one standard range for this test — each lab prints its own. Use the range shown next to your result.
Related guides
- Guide
Why the same blood test has different "normal" ranges at different labs
Reference intervals are built from each lab's own population and equipment, which is why two labs can print different ranges for the same sample.
- Guide
Reference interval, cutoff, and the "optimal" numbers online: three different things
The range beside your result, the target a website quotes, and the threshold that defines a condition are built in different ways and answer different questions.
- Guide
Why the same lab printed a different reference range for you this year
Ranges are not fixed constants. The lab can change method, revise its reference group, or apply a range that depends on your age — none of which is an error.
- Guide
Ferritin, serum iron, TIBC and transferrin saturation: four views of iron
An iron panel measures iron in circulation, iron in storage, and the capacity to carry it — plus a percentage computed from two of them.
- Guide
What a "calculated" result means, and which of your numbers are one
Several values on a routine report were never measured — they are arithmetic on other rows. Which ones, how to spot them, and why it matters when they change.