What Is Ferritin?
Ferritin is a protein that stores iron in your cells. A serum ferritin test reflects your total iron stores.
Ferritin is more informative than hemoglobin alone. Hemoglobin drops when you're already anemic. Ferritin declines much earlier, when iron stores are being depleted but red blood cell production is still maintained.
Why Ferritin Matters More Than Hemoglobin
When ferritin is low but hemoglobin is still normal, symptoms include:
- Fatigue and low energy
- Brain fog
- Hair loss
- Cold intolerance
- Restless legs
- Exercise intolerance
Ferritin Also Signals Inflammation
Ferritin is an acute phase reactant — it rises in response to inflammation, infection, liver disease. A high ferritin can indicate iron excess or an inflammatory process.
Ferritin Reference Ranges
Men: 30–400 µg/L normal, optimal 50–150. Women: 15–200 µg/L normal, optimal 50–100. Functional deficiency (symptoms common) below 50 µg/L in men, below 30 in women.
How to Address Low Ferritin
- Dietary iron — red meat, organ meat, shellfish, legumes with vitamin C
- Avoiding iron inhibitors around meals
- Iron supplementation — ferrous bisglycinate is generally better tolerated
- IV iron infusion — for severe deficiency
Is Ferritin Tested in a Standard Physical?
Not routinely. Stem Health includes ferritin and iron studies in every Core and Horizon Assessment.
