Iron, serum
Serum iron is how much iron is in the blood right now. It swings a lot during the day, so iron stores are better seen from ferritin.
At a glance
- Sample
- Blood
- Units
- µg/dL (US), µmol/L (Europe)
- Often looked at with
- Ferritin, Transferrin, TIBC, Transferrin saturation
- Preparation
- Labs usually ask you to come in the morning, fasting: the iron level changes during the day, and food can raise it.
Units: µg/dL and µmol/L
US labs usually print iron in µg/dL, most European labs in µmol/L. To convert, divide µg/dL by 5.5845.
µmol/L = µg/dL ÷ 5.5845 · molar mass 55.845 g/mol
This converter changes units only. It doesn’t tell you whether a number is in or out of any range: that depends on the range printed by your own lab, and on your doctor. Soma does not diagnose and is not medical advice.
Why lab ranges differ
Each lab sets its reference range for its own method and analyser, and many ranges differ by age and sex. Two labs can print different ranges for the same blood, so a result is read against the range on its own report, not against a number from another lab or a website.
Soma charts every iron result against the range printed by the lab that measured it.
What can affect the result
- Time of day: higher in the morning, lower in the evening.
- Iron supplements the day before.
- Meat the day before.
- Hemolysis: red cells breaking down in the tube.
If something like this applies, mention it to the doctor who reads your results.
Questions
How do I convert iron from µg/dL to µmol/L?
Divide µg/dL by 5.5845. For example, 100 µg/dL is 17.9 µmol/L.
Why does my lab’s iron range differ from another lab’s?
Each lab sets its range for its own method and equipment, and many ranges differ by age and sex. That’s why a result is best read against the range printed on the same report.
How do I prepare for a iron test?
Labs usually ask you to come in the morning, fasting: the iron level changes during the day, and food can raise it. Follow your lab’s instructions.
Related tests
Got a lab report with Iron?
Share it to Soma: it reads every row on your phone, with no account and no upload, and puts your iron on one chart with your earlier results, each against the range your lab printed.
Sources
- Iron Tests — MedlinePlus, U.S. National Library of Medicine.
- Units: PubChem: Iron (iron), molar mass 55.845 g/mol, as the Soma app converts.
Mention of a source doesn’t mean it endorses Soma. This page explains the test; it doesn’t diagnose and is not medical advice. Talk to your doctor about what your results mean.