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%
With inflammation (ASH 2026): TSAT <20% or ferritin <100 µg/L may suggest iron deficiency
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.
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
9 sources · Most recent publication: 2026
📋
Guideline
Expert society and guideline recommendations
4
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 4 guidelines, 4 reviews, 1 observational study.
📝 Questions to Ask Your Doctor
Be prepared for your appointment. Add questions to your list.
📋 References
[PMID: 42747316] American Society of Hematology 2026 guidelines for diagnosis of iron deficiency. Blood Advances, 2026.
[PMID: 39011129] Recommendations for diagnosis, treatment, and prevention of iron deficiency and iron deficiency anemia. HemaSphere, 2024.
[PMID: 35662478] EASL Clinical Practice Guidelines on haemochromatosis. J Hepatol, 2022.
⚖️ 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.