Ferritin
Ferritin tracks body iron stores and rises with inflammation. WHO defines iron deficiency as below 15 ng/mL in healthy adults, while other sources propose 25 to 45, and laboratory lower limits for women sit near 11. In trials, iron eased fatigue in adults with low ferritin and no anemia. Results differed by about 23% between assays in one comparison.
- Status
- A blood test ordered by a clinician and also sold direct to consumers by some US laboratories. FDA classifies ferritin immunological test systems, which aid in diagnosing conditions such as hemochromatosis and iron deficiency anemia, as class II devices [1].
- Measures
- The concentration of ferritin, an iron-storage protein, in serum or plasma, which in the absence of inflammation rises and falls with the size of the body's iron stores [1][2].
- Also called
- serum ferritin, plasma ferritin, ferritin level, ferritin serum, FERR, iron stores test, storage iron
- Tested for
- iron deficiency, iron stores, fatigue, hair loss, heavy periods, anemia workup, iron overload, hemochromatosis, checking an iron supplement
Strong several reviews agree · Moderate one review or consistent trials · Limited one or a few small studies · Untested no study in people, listed with what it rests on
Linked in research3
- ModerateShown in trials: iron given to adults with low ferritin and no anemia reduced self-rated fatigue, with no change in measured physical capacity.
- ModerateLinked to more type 2 diabetes at higher levels, 73% more in the top fifth than the bottom fifth across pooled cohorts.
- ModerateLinked to liver damage in people with the hemochromatosis genotype, where ferritin of 1,000 ng/mL or more marks those at higher risk.
Reported risks0
No risks sourced yet.
Reference ranges
Each range is the one its source published, in ng/mL. Also reported in µg/L. Where sources differ, each is shown.
World Health Organization guideline, 2020, apparently healthy women and girls aged 5 and older
Apparently healthy females aged 5 and older who are not pregnant · [2]
| Range | What the source calls it |
|---|---|
| below 15 ng/mL | "iron deficiency" |
| 15 to 150 ng/mL | No name given |
| above 150 ng/mL | "risk of iron overload" |
WHO prints its cut-offs in µg/L, which equals ng/mL. It states that the available studies were not sufficient to justify changing its earlier cut-off values, and that markers of inflammation are to be assessed along with ferritin. It gives no term for results between the two cut-offs [2].
World Health Organization guideline, 2020, apparently healthy men and boys aged 5 and older
Apparently healthy males aged 5 and older · [2]
| Range | What the source calls it |
|---|---|
| below 15 ng/mL | "iron deficiency" |
| 15 to 200 ng/mL | No name given |
| above 200 ng/mL | "risk of iron overload" |
The deficiency cut-off is the same as for women. The cut-off for risk of iron overload is higher. WHO defines apparently healthy as physical well-being for age and physiological status without detectable disease [2].
World Health Organization guideline, 2020, apparently healthy children under 5
Apparently healthy infants and children from birth to 59 months · [2]
| Range | What the source calls it |
|---|---|
| below 12 ng/mL | "iron deficiency" |
| 12 or above ng/mL | No name given |
WHO gives no cut-off for risk of iron overload in this age group, so this block does not classify high results [2].
World Health Organization guideline, 2020, people aged 5 and older with infection or inflammation
People aged 5 and older with infection or inflammation, or otherwise not apparently healthy · [2]
| Range | What the source calls it |
|---|---|
| below 70 ng/mL | "iron deficiency" |
| 70 to 500 ng/mL | No name given |
| above 500 ng/mL | "risk of iron overload" |
WHO raises the deficiency cut-off because ferritin rises with infection and inflammation. Its table sets the 70 cut-off for individuals with infection or inflammation and the 500 cut-off for non-healthy individuals. It notes that a level above 500 in non-healthy adults may indicate risk of iron overload or other disease, and calls for further evaluation to establish the cause [2].
World Health Organization guideline, 2020, children under 5 with infection or inflammation
Infants and children from birth to 59 months with infection or inflammation · [2]
| Range | What the source calls it |
|---|---|
| below 30 ng/mL | "iron deficiency" |
| 30 or above ng/mL | No name given |
WHO gives no cut-off for risk of iron overload in this age group [2].
World Health Organization guideline, 2020, first trimester of pregnancy
Pregnant women in the first trimester · [2]
| Range | What the source calls it |
|---|---|
| below 15 ng/mL | "iron deficiency" |
| 15 or above ng/mL | No name given |
WHO gives a cut-off for the first trimester only. It notes that a rise in acute phase proteins, plasma volume expansion in the second trimester and changes in inflammatory measures in the final trimester may all shift the threshold later in pregnancy [2].
American Gastroenterological Association technical review, 2020
Adults with anemia, defined as hemoglobin below 13 g/dL in men and below 12 g/dL in nonpregnant women · [3]
| Range | What the source calls it |
|---|---|
| below 45 ng/mL | "iron deficiency" |
| 45 or above ng/mL | No name given |
Set for diagnosing iron deficiency as the cause of anemia, against bone marrow iron. The review identified 45 ng/mL as the cutoff that balanced sensitivity and specificity, missing fewer cases than 15 ng/mL at the cost of more false positives. It cautions that ferritin can be falsely high in inflammatory disease and hard to interpret in chronic kidney disease, after transfusion or during iron therapy [3].
US national survey analysis of physiologically based thresholds, 2021, women
Non-pregnant women aged 15 to 49 without signs of infection, inflammation or liver disease · [4]
| Range | What the source calls it |
|---|---|
| below 25 ng/mL | "iron deficiency" |
| 25 or above ng/mL | No name given |
Derived from the ferritin level at which hemoglobin began to fall (25.2 ng/mL) and soluble transferrin receptor began to rise (24.0 ng/mL) in 7,498 US women. The authors offer about 25 ng/mL as a potential threshold for consideration, not as an adopted standard, and call for validation outside the US [4].
US national survey analysis of physiologically based thresholds, 2021, young children
Children aged 12 to 59 months without signs of infection · [4]
| Range | What the source calls it |
|---|---|
| below 20 ng/mL | "iron deficiency" |
| 20 or above ng/mL | No name given |
Derived the same way in 2,569 US children, with thresholds of 19.9 and 20.0 ng/mL from the two indicators. The authors contrast it with the WHO cut-off of 12, which they describe as based on expert opinion [4].
Laboratory reference intervals, median lower limit of the five most used assays, 2024 systematic review, women
Adult women, as the lower limit printed on laboratory reports · [5]
| Range | What the source calls it |
|---|---|
| below 11 ng/mL | "below the lower limit of normal" |
| 11 or above ng/mL | No name given |
A summary across assays, so the limit on any one laboratory report may differ. The review found the lower limit for women had a median of 11 ng/mL (interquartile range 9 to 12) for the five most used commercial assays and 8 ng/mL across 37 published studies. It judged the underlying studies at high risk of bias because about half did not screen out people at risk of iron deficiency, and it did not summarize upper limits, so this block does not classify high results [5]. A review for the American Society of Hematology argues that such ranges underdiagnose iron deficiency in women and that several lines of evidence point to a physiologic cutoff of 50 ng/mL [6].
Laboratory reference intervals, median lower limit of the five most used assays, 2024 systematic review, men
Adult men, as the lower limit printed on laboratory reports · [5]
| Range | What the source calls it |
|---|---|
| below 22 ng/mL | "below the lower limit of normal" |
| 22 or above ng/mL | No name given |
The review found the lower limit for men had a median of 22 ng/mL (interquartile range 22 to 24) for the five most used commercial assays and 25 ng/mL across published studies. It did not summarize upper limits, so this block does not classify high results [5].
What has been shown to move it
Shown to raise it3
Raising iron stores
Shown to raise ferritin in iron-deficient adults and athletes without anemia, most in those starting with very low ferritin.
The numbers and sources
- Effect
- In iron-deficient non-anemic endurance athletes, iron raised serum ferritin (Hedges' g 1.088, 95% CI 0.914 to 1.263) and hemoglobin (g 0.695) [1]. In 13 trials of athletes, oral iron raised ferritin (SMD 1.27, 95% CI 0.44 to 2.10) and did not significantly change hemoglobin (SMD 1.31, 95% CI -0.29 to 2.93) [2]. In non-anemic iron-deficient adults, ferritin rose by 9.23 (95% CI 6.48 to 11.97) and hemoglobin by 4.01 g/L [3].
- Population
- 17 studies of endurance athletes [1]; 449 athletes in 13 RCTs [2]; 1,170 patients in 18 trials [3].
- Sources
- [1], [2], [3]
- Caveats
- In [2], the ferritin rise was evident in athletes starting at 12 µg/L or below, with minimal effect at higher starting ferritin.
Anemia in pregnancy
Shown to halve anemia risk in non-anemic pregnant women, with no change in birth weight or preterm birth.
The numbers and sources
- Effect
- In 23 studies of 4,492 non-anemic pregnant women, oral iron raised hemoglobin by 6.95 g/L (95% CI 4.81 to 9.09) and ferritin by 12.22 ng/mL, and halved the risk of anemia (RR 0.50, 95% CI 0.34 to 0.74, high certainty, number needed to treat 10). Birth weight, preterm birth and cesarean section did not differ [7].
- Population
- Non-anemic pregnant women in RCTs and observational studies [7].
- Sources
- [7]
- Caveats
- Heterogeneity was high for hemoglobin (I² 91%) and ferritin (I² 87%). Reporting of harms was inconsistent, and the authors found too little evidence to judge them [7].
Iron deficiency anemia
Shown to raise serum iron, ferritin and hemoglobin more than ferrous sulfate in people with iron deficiency anemia.
The numbers and sources
- Effect
- Compared with ferrous sulfate, lactoferrin raised serum iron by 41.44 µg/dL and ferritin by 13.60 ng/mL more, and raised hemoglobin more. Fractional iron absorption was 2.08 percentage points lower and IL-6 was 45.59 pg/mL lower [5]. In 8 controlled trials in children with or without anemia, adding bovine lactoferrin to iron raised serum ferritin by 3.52 µg/L more than iron alone (95% CI 0.66 to 6.38), with no difference in hemoglobin, serum iron or transferrin receptor [6].
- Population
- Intervention studies in people with iron deficiency anemia [5]. Children in 8 trials [6].
- Sources
- [5], [6]
- Caveats
- The first abstract does not give the number of trials or participants [5]. The second compared lactoferrin plus iron with iron alone, not lactoferrin with iron [6].
How it compares with the reference method
Matched the reference method1
Detecting iron deficiency against bone marrow iron
Shown to detect absent bone marrow iron with 79% sensitivity and 98% specificity at 30 ng/mL in people presenting for medical care.
The numbers and sources
- Compared with
- Iron content of a bone marrow sample
- Effect
- A Cochrane review found that in adults presenting for medical care, a fixed threshold of 30 ng/mL had a pooled sensitivity of 79% (95% CI 58 to 91) and specificity of 98% (95% CI 91 to 100) across 9 studies. In apparently healthy adults, three studies reported sensitivities of 63% to 100% and specificities of 92% to 98% at cutoffs that varied by study [13]. A technical review for a gastroenterology society, in patients with anemia, found sensitivity of 0.59 and specificity of 0.99 at 15 ng/mL, and sensitivity of 0.85 and specificity of 0.92 at 45 ng/mL [3].
- Population
- 512 participants in the 9 studies at 30 ng/mL, within 72 studies of 6,059 participants on iron deficiency [13]. Outpatients with anemia [3].
- Sources
- [13], [3]
- Caveats
- The Cochrane authors rate the certainty as low for people presenting for care and very low for apparently healthy people, and find too little evidence to say how ferritin performs when screening people without symptoms. For iron overload they rate the evidence as very low certainty [13].
Mixed results2
Agreement between assays and laboratories
Mixed results: a 2018 meta-analysis judged ferritin methods comparable, while a 2022 comparison of four widely used systems found results differed by a median 23%.
The numbers and sources
- Compared with
- Other ferritin measuring systems, and a WHO international standard
- Effect
- A meta-analysis of 148 studies found within-run imprecision of 6.2%, between-run imprecision of 8.9% and a pooled regression coefficient of 0.985 between methods, and concluded that the most used methods have comparable accuracy [16]. A later comparison of four widely used measuring systems on 39 serum pools found highly significant differences, with a median between-assay coefficient of variation of 22.9% (interquartile range 21.8 to 25.5). Only one system correctly recovered the assigned value of the WHO international standard [17]. Across 52 certified Dutch laboratories, reference intervals differed widely even on the same platform. Applied to the same results, the share of premenopausal women falling below the reference limit ranged from 11% to 53%, and of men from 2% to 19% [18].
- Population
- 148 method comparison studies [16]. 39 human serum pools on 4 measuring systems [17]. 52 laboratories and about 1.09 million ferritin results from primary care [18].
- Sources
- [16], [17], [18]
- Caveats
- The authors of the 2022 comparison note that manufacturers calibrate to different WHO standards that are not traceable to each other [17]. A result near a cut point may be classified differently by another laboratory [18].
Week to week variation in one person
One small study found ferritin varied about 17% from week to week within the same person over five weeks.
The numbers and sources
- Compared with
- The same person's results on 5 weekly draws
- Effect
- Within-person variation was 16.9% (95% CI 14.4 to 20.2), variation between people was 132% and analytical variation was 3.5%. The authors calculated that two results in one person need to differ by 47.8% to exceed expected variation [19].
- Population
- 22 apparently healthy volunteers aged 18 to 55 in Turkey, sampled once a week for five weeks [19].
- Sources
- [19]
- Caveats
- Twenty-two people and one laboratory. The study states no threshold for agreement, so the result is given as numbers only [19].
Did not match the reference method1
Effect of inflammation on the result
Shown to read about 30% higher when inflammation markers are raised, which hides iron deficiency in a share of people.
The numbers and sources
- Compared with
- Ferritin in people in the same studies without raised inflammation markers
- Effect
- In a meta-analysis of 32 studies of apparently healthy people, ferritin was 49.6% higher with C-reactive protein above 5 mg/L and 38.2% higher with raised alpha-1-acid glycoprotein. Across stages it was 30% higher in the incubation stage, 90% higher in early convalescence and 36% higher in late convalescence. Overall, inflammation raised ferritin by about 30% and led to a 14% underestimate of iron deficiency (95% CI 7 to 21) [14]. In pooled survey data, the share of people with depleted iron stores was 4% in the highest tenth of C-reactive protein and 30% in the lowest among preschool children, and 6% against 29% among women of reproductive age. Adjusting for inflammation raised the estimated prevalence by 7 to 25 percentage points in children and 2 to 8 points in women [15]. WHO sets higher deficiency cut-offs for people with infection or inflammation for this reason [2].
- Population
- 8,796 infants, children, men and women in 32 studies [14]. 27,865 preschool children in 15 surveys and 24,844 women in 8 surveys [15].
- Sources
- [14], [15], [2]
- Caveats
- The surveys' authors state that more work is needed to validate the adjustment methods, and WHO notes that different adjustment approaches give widely varying prevalence estimates [15][2].
What studies tie it to
Linked in research3
Fatigue in adults with low ferritin and no anemia
Shown in trials: iron given to adults with low ferritin and no anemia reduced self-rated fatigue, with no change in measured physical capacity.
The numbers and sources
- Effect
- In a meta-analysis of randomized trials in iron-deficient adults without anemia, iron supplementation reduced self-reported fatigue (standardized mean difference -0.38, 95% CI -0.52 to -0.23, 4 trials, 714 participants). Maximal oxygen consumption did not differ (SMD 0.11, 95% CI -0.15 to 0.37, 9 trials, 235 participants), nor did timed exercise tests [7]. In one of the larger trials, in women with unexplained fatigue and ferritin below 50 ng/mL, the fatigue score fell 47.7% with iron and 28.8% with placebo (difference -18.9%, 95% CI -34.5 to -3.2), with no effect on quality of life, depression or anxiety [8].
- Population
- 1,170 adults in 18 trials [7]. 198 menstruating women aged 18 to 53 with hemoglobin above 12.0 g/dL, treated for 12 weeks [8].
- Sources
- [7], [8]
- Caveats
- Fatigue was self-rated, and the larger trial was observer-blinded with closed labels, not fully double-blind [8]. Trials defined iron deficiency by different ferritin cut points.
Type 2 diabetes at high levels
Linked to more type 2 diabetes at higher levels, 73% more in the top fifth than the bottom fifth across pooled cohorts.
The numbers and sources
- Effect
- In a meta-analysis of prospective studies, the fully adjusted relative risk of type 2 diabetes was 1.73 (95% CI 1.35 to 2.22) comparing extreme fifths of baseline ferritin, with heterogeneous findings between studies (I² 58%). In dose-response analysis, each 5 ng/mL higher ferritin had a relative risk of 1.01 (95% CI 0.99 to 1.02) [10].
- Population
- 9 prospective studies of ferritin, within a review of 12 studies with 185,462 participants and 11,079 new cases of type 2 diabetes [10].
- Sources
- [10]
- Caveats
- Observational, and the authors state that causality is not established. The per-unit estimate did not reach significance [10].
Organ damage in hereditary hemochromatosis
Linked to liver damage in people with the hemochromatosis genotype, where ferritin of 1,000 ng/mL or more marks those at higher risk.
The numbers and sources
- Effect
- Among people homozygous for the HFE C282Y variant followed for an average of 12 years, documented disease related to iron overload developed in 28.4% of men (95% CI 18.8 to 40.2) and 1.2% of women (95% CI 0.03 to 6.5). Men with the genotype and ferritin of 1,000 ng/mL or more were more likely to report fatigue, use of arthritis medicine and a history of liver disease than men without the variant [11]. A liver society guideline reports that fewer than 2% of people with HFE hemochromatosis and ferritin below 1,000 ng/mL at diagnosis have bridging fibrosis or cirrhosis in the absence of other conditions, a 94% negative predictive value. It also cites a review in which 64% of patients referred with ferritin over 1,000 ng/mL did not have iron overload on biopsy [12].
- Population
- 203 C282Y homozygotes among 31,192 people of northern European descent aged 40 to 69 [11]. Studies summarized in an Asian Pacific guideline [12].
- Sources
- [11], [12]
- Caveats
- Applies to people who carry the genotype. In people referred for a high ferritin without it, most did not have iron overload [12].
Mixed results2
Death from any cause at high levels
Mixed results: one Danish cohort linked ferritin of 600 ng/mL or more to 50% more deaths, while a pooled analysis of population studies found no link.
The numbers and sources
- Effect
- In a Danish general population cohort, the adjusted hazard ratio for death was 1.1 (95% CI 1.1 to 1.2) for ferritin of 200 ng/mL or more against less than 200, and 1.5 (95% CI 1.2 to 1.8) for 600 or more. Median survival was 55 years at 600 or more, 72 years at 400 to 599, 76 years at 200 to 399 and 79 years below 200. For 600 or more, hazard ratios were 1.6 for cancer death and 1.5 for cardiovascular death. The same paper's meta-analysis of population studies comparing the top with the reference quartile or third found an odds ratio for death of 1.0 (95% CI 0.9 to 1.1) [9].
- Population
- 8,988 adults in the Copenhagen City Heart Study, 6,364 deaths over a median 23 years [9].
- Sources
- [9]
- Caveats
- Observational. Ferritin rises with infection and inflammation [2][3], so a high level may mark disease already present and need not reflect iron itself.
Heavy menstrual bleeding
Limited evidence: heavier menstrual loss went with lower ferritin in Northern European but not East Asian women, and half of adolescents referred for heavy periods had low ferritin.
The numbers and sources
- Effect
- In healthy premenopausal women of genetically confirmed ancestry, a higher menstrual blood loss score went with lower serum ferritin (β -0.01 on the log scale, P = 0.004), lower total body iron and higher soluble transferrin receptor in women of Northern European ancestry, and with none of these in women of East Asian ancestry [20]. Of 114 young women referred to a US hematology clinic for heavy menstrual bleeding, 50.9% had ferritin below 20 ng/mL, and fewer than half of those were anemic [21]. In an Australian screening study of active women, 51 of the 104 who had follow-up iron tests (about 49%) had ferritin below 30 ng/mL, and women reporting a history of iron deficiency were more likely to report heavy menstrual bleeding, 36.9% of them [22].
- Population
- Premenopausal women aged 18 to 50 with a body mass index of 18 to 30 in the FeGenes study [20]. 114 girls and young women aged 9 to 19 [21]. 1,042 active women aged 18 to 65 [22].
- Sources
- [20], [21], [22]
- Caveats
- Observational and cross-sectional. Menstrual loss was scored from questionnaires, not measured, and the referred adolescents had no comparison group without heavy bleeding [20][21]. In the screening study, only women with low or borderline hemoglobin had iron tests [22]. The FeGenes abstract does not give the number of women [20].
Sources
- US Food and Drug Administration. 21 CFR 866.5340, Ferritin immunological test system. Electronic Code of Federal Regulations. https://www.ecfr.gov/current/title-21/section-866.5340
- World Health Organization. WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations. Geneva: World Health Organization, 2020. ISBN 978-92-4-000012-4. https://www.who.int/publications/i/item/9789240000124
- Rockey DC, Altayar O, Falck-Ytter Y, Kalmaz D. AGA Technical Review on Gastrointestinal Evaluation of Iron Deficiency Anemia. Gastroenterology. 2020. https://doi.org/10.1053/j.gastro.2020.06.045
- Mei Z, Addo OY, Jefferds ME, et al. Physiologically based serum ferritin thresholds for iron deficiency in children and non-pregnant women: a US National Health and Nutrition Examination Surveys (NHANES) serial cross-sectional study. The Lancet Haematology. 2021. https://doi.org/10.1016/S2352-3026(21)00168-X
- Truong J, Naveed K, Beriault D, et al. The origin of ferritin reference intervals: a systematic review. The Lancet Haematology. 2024. https://doi.org/10.1016/S2352-3026(24)00103-0
- Martens K, DeLoughery TG. Sex, lies, and iron deficiency: a call to change ferritin reference ranges. Hematology, American Society of Hematology Education Program. 2023. https://doi.org/10.1182/hematology.2023000494
- Houston BL, Hurrie D, Graham J, et al. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open. 2018. https://doi.org/10.1136/bmjopen-2017-019240
- Vaucher P, Druais PL, Waldvogel S, Favrat B. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. Canadian Medical Association Journal. 2012. https://doi.org/10.1503/cmaj.110950
- Ellervik C, Marott JL, Tybjærg-Hansen A, et al. Total and Cause-Specific Mortality by Moderately and Markedly Increased Ferritin Concentrations: General Population Study and Metaanalysis. Clinical Chemistry. 2014. https://doi.org/10.1373/clinchem.2014.229013
- Kunutsor SK, Apekey TA, Walley J, Kain K. Ferritin levels and risk of type 2 diabetes mellitus: an updated systematic review and meta-analysis of prospective evidence. Diabetes/Metabolism Research and Reviews. 2013. https://doi.org/10.1002/dmrr.2394
- Allen KJ, Gurrin LC, Constantine CC, et al. Iron-Overload-Related Disease in HFE Hereditary Hemochromatosis. New England Journal of Medicine. 2008. https://doi.org/10.1056/NEJMoa073286
- Crawford DHG, Ramm GA, Bridle KR, et al. Clinical practice guidelines on hemochromatosis: Asian Pacific Association for the Study of the Liver. Hepatology International. 2023. https://doi.org/10.1007/s12072-023-10510-3
- Garcia-Casal MN, Pasricha SR, Martinez RX, et al. Serum or plasma ferritin concentration as an index of iron deficiency and overload. Cochrane Database of Systematic Reviews. 2021. https://doi.org/10.1002/14651858.CD011817.pub2
- Thurnham DI, McCabe LD, Haldar S, et al. Adjusting plasma ferritin concentrations to remove the effects of subclinical inflammation in the assessment of iron deficiency: a meta-analysis. The American Journal of Clinical Nutrition. 2010. https://doi.org/10.3945/ajcn.2010.29284
- Namaste SM, Rohner F, Huang J, et al. Adjusting ferritin concentrations for inflammation: Biomarkers Reflecting Inflammation and Nutritional Determinants of Anemia (BRINDA) project. The American Journal of Clinical Nutrition. 2017. https://doi.org/10.3945/ajcn.116.141762
- Garcia-Casal MN, Peña-Rosas JP, Urrechaga E, et al. Performance and comparability of laboratory methods for measuring ferritin concentrations in human serum or plasma: A systematic review and meta-analysis. PLOS ONE. 2018. https://doi.org/10.1371/journal.pone.0196576
- Braga F, Pasqualetti S, Frusciante E, et al. Harmonization Status of Serum Ferritin Measurements and Implications for Use as Marker of Iron-Related Disorders. Clinical Chemistry. 2022. https://doi.org/10.1093/clinchem/hvac099
- Kurstjens S, van Dam AD, Oortwijn E, et al. Inconsistency in ferritin reference intervals across laboratories: a major concern for clinical decision making. Clinical Chemistry and Laboratory Medicine. 2025. https://doi.org/10.1515/cclm-2024-0826
- Ozkanay H, Arslan FD, Narin F, Koseoglu MH. Biological variation of plasma 25-Hydroxyvitamin D3, serum vitamin B12, folate and ferritin in Turkish healthy subject. Scandinavian Journal of Clinical and Laboratory Investigation. 2023. https://doi.org/10.1080/00365513.2023.2278537
- Lee MR, Barad A, Bender E, et al. Differential associations between menstrual blood loss scores and iron status in East Asian and Northern European individuals: findings from a cross-sectional analysis of the Iron Genes in East Asian and Northern European Adults Study (FeGenes) cohort. The American Journal of Clinical Nutrition. 2026. https://doi.org/10.1016/j.ajcnut.2026.101326
- Johnson S, Lang A, Sturm M, O'Brien SH. Iron Deficiency without Anemia: A Common Yet Under-Recognized Diagnosis in Young Women with Heavy Menstrual Bleeding. Journal of Pediatric and Adolescent Gynecology. 2016. https://doi.org/10.1016/j.jpag.2016.05.009
- Dugan C, Peeling P, Davies A, et al. The relationship between menorrhagia, iron deficiency, and anaemia in recreationally active females: An exploratory population based screening study. Journal of Science and Medicine in Sport. 2024. https://doi.org/10.1016/j.jsams.2024.04.012