Serum Iron
Serum iron reflects circulating iron bound to transferrin at the time of sampling. Population values vary by sex and age, but the distribution is also shaped by diurnal variation and recent iron intake.
Unit: µg/dL · 12 groups · age and sex · 1 source
Filed under panels: Iron Studies · topics: Hematology
Serum Iron by age and sex
| Age (years) | Males (µg/dL) | Females (µg/dL) |
|---|---|---|
| 20-29 | median 89 middle 90% 51 to 169 | median 73 middle 90% 29 to 161 |
| 30-39 | median 90 middle 90% 45 to 153 | median 75 middle 90% 27 to 146 |
| 40-49 | median 93 middle 90% 52 to 170 | median 76 middle 90% 26 to 146 |
| 50-59 | median 90 middle 90% 50 to 159 | median 81 middle 90% 37 to 140 |
| 60-69 | median 90 middle 90% 43 to 148 | median 83 middle 90% 46 to 135 |
| 70+ | median 87 middle 90% 43 to 149 | median 79 middle 90% 41 to 127 |
Download Serum Iron percentiles (CSV) Values at full stored precision; tables on this site may round for display. Licensed under CC BY 4.0.
Population Distribution
These pages use serum iron from the NHANES iron-status dataset. Serum iron measures the amount of iron circulating in blood bound to transferrin. Because it shifts with time of day, inflammation, supplementation, and recent intake, it is typically interpreted together with ferritin, TIBC, and transferrin saturation rather than in isolation.
Frequently Asked Questions
Why is serum iron more variable than ferritin?
Serum iron changes over short time scales with diurnal rhythms, inflammation, recent intake, and iron supplementation. Ferritin is usually more stable because it reflects stored iron rather than momentary circulating iron.
Should serum iron be interpreted alone?
Usually no. Serum iron is most informative when interpreted alongside ferritin, TIBC, and transferrin saturation, which together describe iron stores and transport capacity.
How do I convert µg/dL to µmol/L?
Multiply by 0.179. For example, 100 µg/dL is approximately 17.9 µmol/L.
Data Sources
Cite this data
LabNorms. Serum Iron population percentiles by age and sex. Data: NHANES 2017-March 2020 Pre-Pandemic. https://labnorms.com/analytes/serum-iron/. Licensed under CC BY 4.0. Accessed [date].
Download Serum Iron percentiles (CSV) Values at full stored precision; tables on this site may round for display. Licensed under CC BY 4.0.