Ferritin
A protein that stores iron in your body. The best marker for assessing your iron reserves.
What is Ferritin?
Ferritin is a protein that stores iron inside your cells, primarily in the liver, spleen, and bone marrow. Think of it as your body's iron savings account.
When you need iron — for making red blood cells, for example — your body withdraws from ferritin stores. When you have excess iron, it gets deposited into ferritin for later use.
A ferritin blood test measures how much iron you have in reserve, making it the best single marker for iron status.
Normal Ranges
| Group | Ferritin Level |
|---|---|
| Adult men | 30–400 ng/mL |
| Adult women (premenopausal) | 15–150 ng/mL |
| Adult women (postmenopausal) | 30–200 ng/mL |
Optimal levels may be higher than "normal" minimums. Many clinicians prefer ferritin above 50 ng/mL for optimal energy and function.
Why It Matters
Fatigue Investigation
Low ferritin is one of the most common causes of unexplained fatigue, even when other iron markers look normal. You can be iron-depleted without being anemic.
Hair and Skin Health
Iron deficiency affects hair growth and skin quality. Low ferritin is often found in cases of unexplained hair loss.
Athletic Performance
Athletes need adequate iron for oxygen transport. Low ferritin impairs endurance and recovery.
Inflammation Indicator
Ferritin is also an acute phase reactant — it rises during inflammation, infection, or chronic disease. Very high ferritin may indicate inflammation rather than iron overload.
Low vs. High Ferritin
Low Ferritin (Iron Deficiency)
- Fatigue, weakness
- Hair loss
- Shortness of breath
- Pale skin
High Ferritin
- May indicate iron overload (hemochromatosis)
- Often reflects inflammation or infection
- Can be elevated in liver disease
What Affects Ferritin
- Menstruation — Regular blood loss depletes iron stores
- Diet — Red meat increases iron; vegetarian diets may not provide enough
- Inflammation — Raises ferritin independently of iron status
- Exercise — Intense training increases iron needs
- Vitamin C — Enhances iron absorption
How Often to Test
- Routine screening: Not always included; request it if fatigued
- Women with heavy periods: Annually
- Vegetarians/vegans: Annually
- After iron supplementation: 3 months to reassess
Related Biomarkers
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