Iron Studies — Serum Iron, TIBC and Transferrin Saturation
Iron studies are a group, not a single test: serum iron, TIBC and transferrin saturation, read with ferritin, show whether the iron in your blood is too low or too high.
Iron studies are a group, not a single test: serum iron, TIBC and transferrin saturation, read together with ferritin, show whether the iron in your blood is too low or too high.
The biomarker
- Name: Iron Studies (serum iron, TIBC, transferrin saturation)
- Units: mcg/dL (serum iron, TIBC); % (transferrin saturation)
- Standard range (ranges vary by lab):
- Serum iron: 59–158 mcg/dL (male); female — read against the range your lab reports
- TIBC: 171–505 mcg/dL (male) / 149–492 mcg/dL (female)
- Transferrin saturation: 20–50% (male) / 15–45% (female)
How to read your result
| Pattern | What it may indicate |
|---|---|
| Low iron + high TIBC + low ferritin | Low iron stores (iron deficiency) |
| High iron | Could be a sign of hemochromatosis (iron overload) — followed up by a clinician |
| Ferritin caveat | A high ferritin can also come from liver disease or inflammation, not only from too much iron |
| Daily variation | Blood iron varies through the day and with recent iron intake, which is why the test is usually done in the morning, often fasting |
What moves the needle
- Never supplement on a hunch: iron can be harmful if you get too much, and the body has no natural way to get rid of extra iron.
- Preparation: your provider may ask you to fast for 12 hours before the test, which is usually done in the morning.
- Supplements: tell your clinician about any iron supplements and ask whether to pause them before the draw — recent iron intake changes serum iron.
- If deficient: the cause is looked for, not only the iron replaced — iron deficiency anemia can be a sign of blood loss, especially in adults over 50.
- If overloaded: a raised result goes to a clinician — extra iron is stored in the liver, heart and pancreas and can damage them.
Why this test is worth asking for
- Transferrin saturation, calculated by dividing serum iron by TIBC, adds what serum iron alone cannot show.
- Iron tests can show whether blood iron is too low (a sign of anemia) or too high (a sign of hemochromatosis).
- Whether iron should be replaced or avoided depends on which pattern the panel shows — which is why iron is never taken on a hunch.
Related protocols
- Ferritin — Iron Storage
- CMP — The 14 Numbers on Your Annual Panel
- CBC — What the Full Blood Count Shows
Sources
- MedlinePlus — Iron Tests
- MedlinePlus — Serum iron test (Medical Encyclopedia)
- MedlinePlus — Total iron binding capacity (Medical Encyclopedia)
- MedlinePlus — Ferritin blood test (Medical Encyclopedia)
- MedlinePlus — Iron deficiency anemia
- MedlinePlus — Hemochromatosis
- NIH Office of Dietary Supplements — Iron Fact Sheet for Consumers
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
