What is Transferrin Saturation?
Transferrin saturation (TSAT) is the percentage of transferrin (iron-transport protein) that is saturated with iron. It's calculated as (Serum Iron ÷ TIBC) × 100. TSAT helps diagnose iron deficiency and iron overload disorders.
Interpreting Results
<20%: Iron deficiency likely, especially if ferritin also low. Common in menstruating women, GI bleeding, poor diet.
20-45%: Normal iron status
>45%: Iron overload possible. Consider hemochromatosis (genetic), excessive supplementation, or repeated transfusions.
>60%: High probability of hemochromatosis
Clinical Context
Use TSAT with ferritin for complete iron assessment. Iron deficiency: Low TSAT + low ferritin. Anemia of chronic disease: Low TSAT + normal/high ferritin. Hemochromatosis: High TSAT + high ferritin. TSAT can fluctuate; fasting morning sample is most accurate.
Quick Tips
- BMI alone doesn't reflect overall health
- TDEE varies based on activity level
- Consult a healthcare professional for medical decisions
Frequently Asked Questions
TIBC measures iron-binding capacity; ferritin measures iron stores. Both needed for complete assessment.
If due to iron deficiency, yes. But determine cause first (GI bleeding, heavy periods, etc.).
Yes, inflammation lowers TSAT and iron but raises ferritin, complicating interpretation.
Genetic disorder causing iron overload. Diagnosed with high TSAT (>45%) and high ferritin, confirmed by genetic testing.
If iron deficient: recheck after 3 months of supplementation. If hemochromatosis: every 3-6 months during phlebotomy.