Transferrin carries iron
Biomarker library
Iron Status
Iron
Serum iron is the iron travelling in your blood at the moment of the test, bound to its carrier protein, transferrin.
Measured in your health assessment, with a doctor to explain your result. Book yours
Why it matters
Iron is essential for haemoglobin, for myoglobin in muscle and for the enzymes that make energy, but free iron is toxic, so the body keeps it tightly escorted. Serum iron swings through the day and after meals, so it is never read on its own.
What a result can mean
Lower than the range
A low level can mean iron deficiency, but it also happens with inflammation, when the body deliberately hides iron away from the bacteria that need it to grow. This protective trick is behind the ‘anaemia of inflammation’.
Higher than the range
A high level can follow an iron-rich meal or a supplement taken before the test, or reflect iron overload such as haemochromatosis, liver damage or the breakdown of red cells.
What can help
Because it varies so much, serum iron is interpreted with ferritin and transferrin saturation, and any treatment follows that overall picture. Leaving out iron supplements on the day before the test gives a fairer reading.
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 iron.
Measured in your health assessment and explained by the doctor who reviews your results.