Overview
Ferritin is the protein in which the body stores iron. Its level gives the earliest sign of iron deficiency, before anaemia appears.
Why it's done
It is ordered for fatigue, hair loss, pallor or a low haemoglobin on a CBC.
How to prepare
Preferably in the morning, after light fasting.
What to expect
A venous blood draw.
Understanding the results
A low ferritin confirms iron deficiency; a high value may relate to inflammation or iron overload. It is interpreted together with the CBC.