Serum Iron

The circulating iron available for immediate use.

What it is

Serum iron measures the amount of iron currently in the bloodstream, bound to its transport protein transferrin. It reflects day-to-day iron availability rather than total stores.

Why it matters

In conjunction with ferritin and TIBC (total iron-binding capacity), serum iron helps distinguish true iron deficiency from anaemia of chronic disease — a common issue in cancer patients where ferritin is elevated but iron utilisation is impaired.

How to test

Blood test, ideally fasted (morning). Best interpreted with ferritin and TIBC as a full iron panel.

This information is for educational purposes only. Always discuss testing and interpretation of results with your care team.

Optimal range

Men: 14–30 µmol/L. Women: 10–28 µmol/L.

How often

Every 6 months, or when fatigue or anaemia is suspected.