Iron-binding sites in use
Biomarker library
Iron Status
Transferrin saturation
Transferrin saturation is the percentage of iron-carrying seats that are filled, usually about 20 to 45%.
Measured in your health assessment, with a doctor to explain your result. Book yours
Why it matters
It shows how much iron is available for making red cells right now, while ferritin shows the reserves. Read together, they tell iron deficiency, inflammation and iron overload apart.
What a result can mean
Lower than the range
Below about 20% suggests there isn't enough iron for red-cell production: from iron deficiency if ferritin is low, or from inflammation if ferritin is normal or high.
Higher than the range
Values persistently above about 45% suggest more iron is being absorbed than the body needs. This is the first clue to genetic haemochromatosis, which a simple gene test can confirm. A recent supplement can also raise it.
What can help
A low saturation with low ferritin is treated by replacing iron and finding the cause. A high saturation is repeated on a fasting sample and, if confirmed, investigated for iron overload, which is treated by venesection.
Read it with
NoteGeneral educational illustration. Colours, sizes and movement are simplified. This is not a scan or a simulation of your body. General information, not personal medical advice: a doctor reads your own results with your history.
Know your transferrin saturation.
Measured in your health assessment and explained by the doctor who reviews your results.