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Ferritin & Iron Studies

Ferritin is the body's main iron storage protein and the single best test for iron deficiency. Iron studies together help diagnose anaemia type and iron overload conditions like haemochromatosis.

Written and clinically reviewed by Suman Konda, PharmD, Clinical Pharmacist · Based on peer-reviewed sources · Editorial policy · Not medical advice

Last reviewed and updated: · How we check our content

Ferritin normal (women)
11–307 ng/mL
Ferritin normal (men)
24–336 ng/mL
Iron deficiency
Ferritin <15 µg/L
Haemochromatosis
Ferritin often >1000 µg/L

Iron Panel: What Each Test Shows

TestNormal RangeRole
FerritinMen: 24–336 ng/mL; Women: 11–307 ng/mLIron stores: best single test for deficiency
Serum iron10–30 µmol/LCirculating iron level (fluctuates day-to-day)
TIBC (total iron-binding capacity)45–72 µmol/LIron-carrying capacity of transferrin
Transferrin saturation20–50%% of transferrin bound to iron
Soluble transferrin receptor (sTfR)<1.76 mg/LRises in deficiency; unaffected by inflammation
Iron studies interpretation patternsTypical iron study patterns and the condition each suggests.Why iron tests are read as a patternNo single iron test is diagnostic on its ownSerum ironFerritinTIBCTransferrin sat.Iron deficiencyLowLowHighLowAnaemia of inflammationLowNormal / highLowLowIron deficiency + inflammationLowNormalNormalLowIron overloadHighHighLowHighNormal iron statusNormalNormalNormalNormalFerritin rises with inflammation, so a normal ferritin does not exclude iron deficiency when CRP is raised; transferrin saturation is less affected.
Scroll sideways to see the whole diagram
Iron study patterns and what each combination suggests.
What the table shows. Iron deficiency gives low iron, low ferritin, high TIBC and low transferrin saturation. Anaemia of inflammation looks similar on serum iron but ferritin is normal or high and TIBC is low, because ferritin is an acute-phase protein. The difficult case is the third row, iron deficiency occurring alongside inflammation, where ferritin can sit in the normal range while iron stores are genuinely depleted. That is why ferritin is interpreted next to CRP rather than alone.

Pattern Recognition

PatternFerritinIronTIBCDiagnosis
Iron deficiencyLowLowHighIron deficiency anaemia
Anaemia of chronic diseaseNormal/HighLowLow/NormalChronic disease, inflammation, cancer
HaemochromatosisVery highHighLowIron overload
HaemolysisHigh (acute)HighNormalRBC destruction
Ferritin Is an Acute Phase ReactantFerritin rises with inflammation, infection, or liver disease, even when iron stores are actually low. A ferritin of 80 µg/L in a patient with an active CRP of 100 mg/L may still mask iron deficiency. Check CRP alongside ferritin.
What ferritin level is considered iron deficiency?
Ferritin <15 µg/L confirms iron deficiency. <30 µg/L is suggestive if symptoms are present. In inflammatory states (raised CRP), a higher ferritin threshold (up to 100 µg/L) may still reflect functional deficiency.
Why is my iron low if I eat meat?
Causes of iron deficiency despite adequate diet: blood loss (heavy periods, GI bleeding), poor absorption (coeliac disease, post-gastric surgery), or increased demand (pregnancy). Investigate the cause.
What is haemochromatosis?
A genetic condition (usually HFE gene mutations) causing excessive iron absorption and accumulation in organs: liver, heart, pancreas, joints, skin (bronze pigmentation). Treated with regular venesection (phlebotomy).
How long does it take to correct iron deficiency?
Oral iron supplementation typically raises haemoglobin within 4–8 weeks. Iron stores (ferritin) take 3–6 months to replenish. IV iron works faster and is used when oral iron is not tolerated or absorbed.

Which ferritin threshold actually detects iron deficiency?

Laboratory reference ranges for ferritin often start as low as 15 µg/L in women, but that figure reflects statistical distribution in a population rather than the level at which iron stores are genuinely adequate.

A Cochrane systematic review (Garcia-Casal and colleagues, 2021) pooled 72 studies and examined how well ferritin identifies true iron deficiency confirmed against bone-marrow iron. Using a fixed threshold of 30 µg/L in people presenting for medical care, ferritin had a sensitivity of 79% and a specificity of 98%, meaning a result below 30 is a strong indicator of genuine deficiency.

The practical consequence: a ferritin of 20 µg/L may appear within your laboratory's "normal" range while still representing depleted iron stores, particularly if you have fatigue, hair loss or restless legs. Many clinicians treat below 30 µg/L as deficient, and use a higher target (around 50–100 µg/L) when symptoms persist.

Important caveatFerritin is also an acute-phase protein, so it rises with infection, inflammation and liver disease. A normal or high ferritin does not exclude iron deficiency in someone with an inflammatory condition, which is why CRP and transferrin saturation are often checked alongside it.

References

The clinical information on this page is based on peer-reviewed sources indexed in PubMed, the biomedical literature database of the US National Library of Medicine.

  1. Garcia-Casal MN, Pasricha SR, Martinez RX, Lopez-Perez L, Peña-Rosas JP. Serum or plasma ferritin concentration as an index of iron deficiency and overload. Cochrane Database Syst Rev. 2021;5(5):CD011817. doi:10.1002/14651858.CD011817.pub2 · PMID 34028001
  2. Rusch JA, van der Westhuizen DJ, Gill RS, Louw VJ. Diagnosing iron deficiency: controversies and novel metrics. Best Pract Res Clin Anaesthesiol. 2023;37(4):451-467. doi:10.1016/j.bpa.2023.11.001 · PMID 39764832
  3. Ford J. Red blood cell morphology. Int J Lab Hematol. 2013;35(3):351-7. doi:10.1111/ijlh.12082 · PMID 23480230
  4. Iron Overload and Toxicity. In: StatPearls. Treasure Island (FL): StatPearls Publishing. NCBI Bookshelf NBK526131
  5. Masini G, Graham FJ, Pellicori P, et al. Criteria for iron deficiency in patients with heart failure. J Am Coll Cardiol. 2022;79(4):341-351. doi:10.1016/j.jacc.2021.11.039 · PMID 35086656

Frequently asked questions

Why does my lab's Ferritin & Iron Studies range differ from the one shown here?
Every laboratory sets its own reference interval from the analyser, reagents and reference population it uses, so two labs can publish different Ferritin & Iron Studies intervals and both be correct, even reporting in the same mg/L. Read your result against the range printed on your own report.
Should a borderline Ferritin & Iron Studies result be repeated?
Usually. A value just outside the interval is common in people who are entirely well, since about one in twenty healthy results falls outside any 95% reference range by construction. A borderline Ferritin & Iron Studies is normally rechecked rather than acted on.
Do Ferritin & Iron Studies results from two different laboratories compare directly?
Not reliably. Methods differ, so a change between labs can reflect the assay rather than a change in you. Where Ferritin & Iron Studies is being tracked over time, staying with one laboratory makes the comparison meaningful.

Related reading

Medical Disclaimer: This page is for general education only and does not replace professional medical advice. Always consult a qualified healthcare provider.