Home → Tests → Serum Iron Test
Serum Iron Test
⚠️ Update approaching🔬 Evidence: ModerateHematology
Diğer adları: Fe test, Iron blood test, Iron level
⚠️
Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.
⚡ Key Facts
• Measures the amount of iron bound to transferrin circulating in the blood
• Does not reliably reflect iron status on its own — significant daily variation
• Should be interpreted alongside ferritin, TIBC, and transferrin saturation
• Affected by recent meals and time of day
🧪 What Does This Test Measure?
The serum iron test measures the amount of iron bound to transferrin circulating in the blood, representing only a small and variable fraction of total body iron.
📋 Why Is It Ordered?
Ordered for iron deficiency or iron overload evaluation, transferrin saturation calculation, and as part of a comprehensive iron panel.
🔧 Preparation
Serum iron is affected by daily variation and recent meals. Many laboratories recommend morning fasting collection for the most consistent results.
📊 Reference Ranges
Commonly used approximate ranges:
Men: 65–175 µg/dL (11.6–31.3 µmol/L)
Women: 50–170 µg/dL (9.0–30.4 µmol/L)
⚠️ Significant daily variation exists. Should be interpreted alongside ferritin and TSAT.
⬆️ High Values
Elevated serum iron may be associated with iron overload, hemochromatosis, repeated transfusions, excessive supplementation, or hemolytic anemias.
⬇️ Low Values
Low serum iron may be associated with iron deficiency, chronic disease anemia, inflammation, or inadequate dietary intake.
⚙️ What Can Affect Results?
Daily variation, recent meals, fasting duration, inflammation, iron supplements, and assay method may affect serum iron results.
🔬 Evidence Summary
Moderate evidence: 2 guidelines, 4 reviews, 2 observational studies.
📚 Most Important Studies on This Topic
✅ Key Takeaways
💡
What you learned: Serum iron fluctuates significantly throughout the day and with meals. It should always be interpreted alongside ferritin and transferrin saturation.
⛔
A serum iron result alone cannot diagnose iron deficiency or iron overload. It must be evaluated with ferritin, TIBC, and clinical context.
🔬 Sources Used on This Page
8 sources · Most recent publication: 2024📋
Guideline
Expert society and guideline recommendations
2
sources
📖
Review
Comprehensive topic evaluation
4
sources
👁
Observational
Observational and cohort studies
2
sources
Overall assessment: Evidence level for this topic is moderate. This page is supported by 2 guidelines, 4 reviews, 2 observational studies.
📝 Questions to Ask Your Doctor
Be prepared for your appointment. Add questions to your list.
📋 References
[PMID: 39011129] Recommendations for diagnosis, treatment, and prevention of iron deficiency and iron deficiency anemia. HemaSphere, 2024.
[PMID: 33285139] Iron deficiency. The Lancet, 2021.
[PMID: 34497146] British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut, 2021.
[PMID: 32418671] The changing landscape of iron deficiency. Molecular Aspects of Medicine, 2020.
[PMID: 30401704] Iron deficiency. Blood, 2019.
[PMID: 28947322] Influence of diurnal variation and fasting on serum iron concentrations in a community-based population. Clinical Biochemistry, 2017.
[PMID: 25946282] Iron-deficiency anemia. N Engl J Med, 2015.
[PMID: 12090432] Diurnal Variation of Serum Iron, Iron-Binding Capacity, Transferrin Saturation, and Ferritin Levels. American Journal of Clinical Pathology, 2002.
Last reviewed: 3/31/2026
Next review: 3/31/2027
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⚖️ This page does not replace medical advice. Make treatment decisions with your doctor.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.
Content is based on scientific studies indexed in PubMed and current clinical guidelines.