BiomarkersFerritin
Blood & iron
Ferritin
Your stored iron
On your report it may say: Serum ferritin
Ferritin is the protein that stores iron, and its blood level is the best routine measure of your iron reserves. Stores often run down before hemoglobin drops, so low ferritin is an early warning.
Typical ranges · ng/mL
Women
Men
µg/L is the same number
Infection and inflammation raise ferritin, so a 'normal' result during illness can hide low iron.
Ranges vary by lab, age and sex. The range printed on your report applies.
If it's low
Your iron reserves are running low, even if hemoglobin is still normal.
Common causes
- Heavy periods
- Vegetarian diet with low iron absorption
- Pregnancy
- Blood donation
- Gut blood loss or absorption problems
What you might notice
- Tiredness
- Hair shedding
- Restless legs
- Brittle nails
- Feeling cold
If it's high
High ferritin can mean inflammation, liver strain or iron overload. Don't take iron if your ferritin is high.
Common causes
- Inflammation or infection
- Fatty liver or alcohol
- Iron overload conditions
- Iron supplements without need
What you might notice
- Often none
- Joint pain or fatigue with iron overload
Testing
- Who should test
- Women with periods, pregnant women, vegetarians, regular blood donors, and anyone tired or losing hair.
- How to prepare
- Morning, fasting test is preferred; avoid testing during an infection.
- When to retest
- 8–12 weeks after starting iron.
What can help
- Iron BisglycinateOnly if ferritin is low · Morning, empty stomach, with vitamin C
- Vitamin CBoosts absorption of plant iron · Anytime; split larger doses
Food sources
See a doctor if ferritin is very low, or high, or if you have unexplained blood loss.
Common questions
Why is my ferritin low when my hemoglobin is normal?
Stores empty first; anaemia comes later.
Can ferritin be too high from supplements?
Yes, which is why iron should only be taken when needed.
Explore further
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Sources
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Build My Nutrition PlanFor general education only, not medical advice. Ranges shown are typical for adults; the range printed on your lab report applies. Talk to a qualified doctor about your results.