Overview.
Iron is essential for oxygen transport, energy production, and countless enzymatic reactions. An iron panel goes beyond simple hemoglobin to reveal your actual iron stores (ferritin), transport capacity (TIBC), and utilization (saturation). This is crucial for detecting iron deficiency before anemia develops, and for identifying iron overload conditions like hemochromatosis.
A complete iron panel measures serum iron (circulating iron), ferritin (iron storage), TIBC (total iron-binding capacity, or transport capacity), and iron saturation (percentage of binding sites filled). Together, these distinguish between iron deficiency, anemia of chronic disease, and iron overload.
What's included.
- Ferritin — normal: 20-200 (W) / 20-300 (M) ng/mL · Iron storage (the most sensitive marker)
- Serum Iron — normal: 60-170 µg/dL · Circulating iron (varies throughout day)
- TIBC — normal: 250-370 µg/dL · Iron transport capacity (inversely related to iron stores)
- Iron Saturation — normal: 20-50 % · Percentage of transferrin carrying iron
Preparation.
Fasting required — 12 hours.
When: Best drawn in the morning (iron levels are highest). Avoid testing during acute illness as inflammation affects ferritin. Results typically available within 24-48 hours.
- Fast for 12 hours for most accurate results
- Morning draw preferred (iron levels fluctuate daily)
- Avoid iron supplements for 24 hours before testing
- Note recent blood donation or transfusion
When it's ordered.
- Anemia or low hemoglobin on CBC
- Fatigue, weakness, or pallor
- Heavy menstrual periods
- Vegetarian or vegan diet evaluation
- Endurance athletes (high iron demand)
- Family history of hemochromatosis
- Chronic kidney disease
- Before and after iron supplementation
Interpretation.
What normal means
Your iron stores are adequate, and iron is being properly transported and utilized. This supports healthy oxygen delivery, energy production, and immune function.
Abnormal patterns
Low ferritin (<20-30) with low iron and high TIBC
Possible causes
- Iron deficiency (most common)
- Blood loss
- Inadequate dietary intake
- Malabsorption
Next steps
- Identify source of loss (GI, menstrual)
- Iron supplementation
- Improve dietary iron intake
- Check for celiac disease
Low/normal iron with low TIBC and normal/high ferritin
Possible causes
- Anemia of chronic disease
- Inflammation
- Chronic kidney disease
Next steps
- Check hs-CRP and inflammatory markers
- Treat underlying condition
- Iron supplementation often not helpful here
High ferritin (>300-500) with high iron saturation (>45%)
Possible causes
- Hemochromatosis (iron overload)
- Transfusion overload
- Liver disease
Next steps
- HFE gene testing for hemochromatosis
- Liver function tests
- Consider therapeutic phlebotomy
- Hematology referral
High ferritin with normal iron/saturation
Possible causes
- Inflammation (ferritin is an acute phase reactant)
- Fatty liver
- Metabolic syndrome
Next steps
- Check hs-CRP
- Liver enzymes and ultrasound
- Address metabolic health
Cost & access.
Iron studies typically cost $30-75 without insurance. Usually covered when investigating anemia or monitoring iron therapy. Often ordered with a CBC for complete evaluation.
FAQs.
Why is ferritin the most important marker?
Ferritin reflects your true iron stores. It drops before hemoglobin does, making it the earliest and most sensitive marker of iron deficiency. It can also identify iron overload.
Can ferritin be normal but iron still be low?
Rarely in true iron deficiency. However, inflammation elevates ferritin even when iron stores are depleted. If you're inflamed and iron-deficient, ferritin may look normal.
What's a good ferritin level for athletes?
Athletes have higher iron demands. Optimal ferritin for athletes is often cited as 50-100 ng/mL for performance, though this is higher than the 'normal' lower limit.
How long does it take to replenish iron stores?
Hemoglobin improves within 2-4 weeks of supplementation, but rebuilding ferritin stores takes 3-6 months. Continue supplementation even after hemoglobin normalizes.