Biomarkers · Hematology

Serum Iron

Both low and high values go with higher risk of death. In NHANES 1999–2018 with linked mortality to 2019, each standard deviation above average goes with 12% lower risk of death. Risk rises at both ends: not comparable

Serum Iron and risk of death

NHANES, our fit with 95% CIPublished curve

Published curve higher than the NHANES fitNHANES fit higher

Risk of death relative to each curve's own reference value, so the two curves need not cross 1 at the same point. The dotted vertical line marks the NHANES median.

Risk of death per SD (NHANES)0.88×95% CI 0.85–0.90 · 48,322 adults, 7,020 deaths

Published risk of death1.37×high vs normal baseline serum iron (95% CI 1.30–1.44) · Taiwan MJ health-screening cohort (1997-2007), followed to 2022

Value of the measurement+0.008gain in concordance within age bands; rank 44 of 56 · all tests

Serum Iron by age and sex

Each bar runs from the 5th to the 95th percentile, the darker part from the 25th to the 75th, and the tick is the median. Not a reference range or a target.

The percentiles as a table

Each row is one sex and age band: the values below which 5%, 25%, 50%, 75% and 95% of people fall (ug/dL), from the survey named in the row. Not a reference range or a target.
Sex	Age	5th	25th	Median	75th	95th	n	Cycle / source
All	20-39	36.0	61.0	82.0	109	165	1,431	NHANES 2017-2018
All	40-59	39.0	65.0	87.0	111	153	1,547	NHANES 2017-2018
All	60+	44.0	66.0	84.0	104	141	1,890	NHANES 2017-2018
All	all	39.0	64.0	84.0	108	154	4,868	NHANES 2017-2018
Men	20-39	48.0	71.0	90.0	116	170	684	NHANES 2017-2018
Men	40-59	50.0	72.0	93.0	116	155	722	NHANES 2017-2018
Men	60+	42.0	71.0	89.0	109	149	958	NHANES 2017-2018
Men	all	48.0	71.0	91.0	113	161	2,364	NHANES 2017-2018
Women	20-39	28.2	52.0	74.0	100	151	747	NHANES 2017-2018
Women	40-59	32.0	58.0	79.8	105	151	825	NHANES 2017-2018
Women	60+	44.0	63.0	81.0	100	132	932	NHANES 2017-2018
Women	all	33.0	57.0	78.0	102	145	2,504	NHANES 2017-2018

What studies found when this marker was changed

They describe what happened in those study groups, not a recommendation. See all catalogued interventions.

Measured changes in Serum Iron, study by study

1 effect with a numeric size, each from one study arm: the dot is the reported change, the line its 95% interval where one was given. Study results in the groups studied, not predictions for a person.

Each row is one study: what was changed, the effect it reported on this marker, and the source.
Type	Intervention	Reported effect	Evidence	Source
pharmacologic	Roxadustat, a prolyl hydroxylase inhibitor, in patients with dialysis-dependent CKD anaemia (network meta-analysis)	Serum iron rose 6.19 ug/dL (95% CI 2.81 to 9.58) with roxadustat in dialysis CKD; duration not stated	meta-analysis	Niu Y, et al. Ren Fail. 2026;48(1):2616572.

Sources

Risk curve: Liu 2025 (PMID 40888985): all-cause HR 1.37 (1.3-1.44) high vs normal baseline serum iron; low vs normal HR 1.27 (1.23-1.31). Scaled to US values (NHANES).
Liu et al. Associations of serum iron and its status change with mortality risk: prospective findings from the MJ cohort. European journal of epidemiology. 2025;40:1419-1429.
NHANES curve: our Cox model adjusted for age and sex, NHANES 1999–2018 with linked mortality to 2019.

Map Serum Iron against another biomarker.

Map Serum Iron against another marker