Home → Tests → Transferrin Saturation

Transferrin Saturation (TSAT)

✅ Up to date🔬 Evidence: ModerateHematology
Diğer adları: Iron saturation, Transferrin sat, TSAT
⚠️

Discuss your test results with your doctor. This page is for informational purposes only and does not provide a diagnosis.

⚡ Key Facts

• A calculated ratio using serum iron and TIBC — not a directly measured value • Indicates what proportion of transferrin is saturated with iron • <20% suggests iron deficiency; >45% suggests possible iron overload • Key parameter in hemochromatosis screening

🧪 What Does This Test Measure?

Transferrin saturation (TSAT) is a calculated value showing what percentage of circulating transferrin molecules are loaded with iron, derived from serum iron divided by TIBC.

📋 Why Is It Ordered?

Ordered for iron deficiency and iron overload evaluation, hemochromatosis screening, and differential diagnosis of anemia.

🔧 Preparation

TSAT is calculated from serum iron and TIBC, so the preanalytical conditions for those two tests apply. Morning fasting collection is generally recommended.

📊 Reference Ranges

Commonly used approximate ranges: Normal: 20–50% Iron deficiency: <20% Iron overload evaluation: >45% ⚠️ Reference ranges may vary by laboratory.

⬆️ High Values

Elevated TSAT may be associated with hereditary hemochromatosis, repeated transfusions, hemolytic anemias, or excessive iron supplementation.

⬇️ Low Values

Low TSAT (<20%) may be associated with iron deficiency, chronic disease anemia, or inflammation.

⚙️ What Can Affect Results?

All factors affecting serum iron (daily variation, meals, inflammation) also affect TSAT. Liver disease and protein status affect TIBC and therefore TSAT.

🔬 Evidence Summary

Moderate evidence: 3 guidelines, 4 reviews, 1 observational study.

✅ Key Takeaways

💡

What you learned: TSAT indicates what proportion of iron-carrying capacity is being used. Low TSAT suggests iron deficiency; high TSAT warrants iron overload evaluation.

⛔

TSAT alone cannot diagnose iron deficiency or iron overload. Ferritin, clinical context, and sometimes genetic testing are needed.

🔬 Sources Used on This Page

8 sources · Most recent publication: 2024
📋
Guideline
Expert society and guideline recommendations
3
sources
📖
Review
Comprehensive topic evaluation
4
sources
👁
Observational
Observational and cohort studies
1
source
Overall assessment: Evidence level for this topic is moderate. This page is supported by 3 guidelines, 4 reviews, 1 observational study.

📝 Questions to Ask Your Doctor

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Last reviewed: 3/31/2026
Next review: 6/30/2026

🔗 Related Topics

🩺 Iron deficiency anemia🧪 Serum iron🧪 Ferritin (Demir depoları)🧪 TDBK (Toplam demir bağlama kapasitesi)🧪 Hemogram (Tam kan sayımı)
⚖️ 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.