Ferritin
A protein that stores iron. A ferritin blood test is often used to estimate the body's iron stores.
Plain English
Ferritin is the iron storage signal.
Why It Matters After 40
Low or high ferritin can matter for fatigue, training tolerance, inflammation, liver context, and iron supplementation decisions.
What To Do With It
Do not start high-dose iron from one AI answer. Ferritin belongs with CBC, iron studies, symptoms, and clinician interpretation.
Human Utility
- Know what the term means before uploading data into an AI tool.
- Separate explanation from medical interpretation.
- Bring trend data and context to the appointment instead of one isolated number.
Proof Structure
It reflects stored iron
MedlinePlus describes ferritin as a protein that stores iron and notes that the blood test can help show whether iron stores are too low or too high.
Source: MedlinePlus ferritin