Evidence quality 4.88/5
Eight-dimension review score against the quality rubric . Each dimension scored 1–5.
- D1 Source grounding
- 5/5
- D2 Source authority
- 5/5
- D3 Arithmetic
- 4/5
- D4 Uncertainty
- 5/5
- D5 Scope
- 5/5
- D6 Prose
- 5/5
- D7 Perception honesty
- 5/5
- D8 Caveat completeness
- 5/5
● your factors — click this risk ▾ to reveal
- Your factors
≈ As likely as
Perceived
Iron deficiency reads to most people as a Victorian complaint -- pale heroines fainting on chaise longues -- or, at most, something a pregnant woman is told to watch. The modern intuition is that a normal diet covers it and that "tired all the time" is about sleep or stress, not blood chemistry. Few menstruating women would guess that roughly one in four of them is running low on iron at any given moment, and that the depletion is a direct arithmetic consequence of monthly blood loss rather than a rare disorder.
Rough estimate: ~5-10% chance for a typical woman
Source: editorial intuition, not polled
Actual
~25.5% of US females aged 12-49 had iron deficiency (inflammation-adjusted serum ferritin <15 µg/L, NHANES 2015-2016)
US females aged 12-49 (NHANES 2015-2016, CDC/NCHS)
Show derivation
The headline is the cited figure itself, un-inflated: Healthy People 2030 sets the national baseline at 25.5% of females aged 12-49 with iron deficiency in 2015-2016, defined as inflammation-adjusted serum ferritin <15 µg/L (CRP-corrected via the BRINDA method). That is a cross-sectional snapshot — at any single blood draw, roughly a quarter of reproductive-age women are below the threshold. Because iron deficiency in this group is driven by recurring menstrual blood loss and the demands of pregnancy, it recurs and remits across a ~35-year reproductive span, so the cumulative probability that a given woman is deficient at SOME point is plausibly higher than the 25.5% snapshot — but that cumulative figure is not separately measured, so it is left as the upper end of the uncertainty band rather than asserted as the headline. The wide band also spans the definitional spread: a stricter 2-of-3-biomarker definition puts non-pregnant prevalence near 9.8% (NHANES 1999-2006), while a higher ferritin cutoff (~25 µg/L) would push it above the headline. The scope is a reproductive-age-woman subgroup, not a general US-adult lifetime — for men and postmenopausal women the figure is a small fraction of this.
Caveats: This entry is scoped to females aged 12-49 — the population the deficiency burde…
This entry is scoped to females aged 12-49 — the population the deficiency burden actually falls on — not to a general US adult, for whom the figure would be a small fraction of this. "Iron deficiency" also depends heavily on where the ferritin line is drawn. Healthy People 2030 uses inflammation-adjusted ferritin <15 µg/L; some recent work argues the physiologically justified threshold for non-pregnant women is closer to ~25 µg/L, which would push prevalence higher still, while older WHO-style 2-of-3 definitions yield the lower ~10% non-pregnant figure. Iron deficiency is also a stage before iron-deficiency anemia: most deficient women are not yet anemic, and the symptom picture (fatigue, poor concentration, cold intolerance) overlaps with much else, so the condition is routinely missed. Ferritin is an acute-phase reactant that rises with inflammation, which is why the CDC applies CRP adjustment; an unadjusted ferritin can mask deficiency in someone with concurrent infection or obesity.
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At any given blood draw, roughly one in four US women of reproductive age is iron deficient. Healthy People 2030 puts the 2015-2016 baseline at 25.5% of females aged 12-49, defined as inflammation-adjusted serum ferritin below 15 µg/L — and sets a national target of merely nudging that to 21.7%. This is not a rare disorder or a relic of another century. It is the predictable arithmetic of monthly blood loss meeting a diet that, for most women, delivers less iron than the 18 mg/day the requirement assumes. Absorption makes it worse: the non-heme iron in plants is taken up at roughly a third the rate of the heme iron in meat, so the women most likely to be cutting red meat are often the ones running closest to empty.
The number moves sharply with circumstance, which is why this entry is scoped to women rather than to “a US adult.” Pregnancy roughly triples requirements and lifts point prevalence from about 9.8% in non-pregnant women to 25.4% in pregnant women in the older NHANES analysis. Heavy menstrual bleeding — clinically, losing more than about 80 mL a cycle — can outpace dietary replacement indefinitely. Frequent blood donation strips 200 mg or more of iron per session. Run the other way and the risk nearly vanishes: for men and postmenopausal women, new iron deficiency is uncommon enough that clinicians treat it as a reason to look for gastrointestinal bleeding, not a dietary footnote. And because the loss recurs cycle after cycle, the snapshot quarter almost certainly understates how many women are iron deficient at some point across their reproductive years — though how far above a quarter that runs has not been directly measured.
None of this means every deficient woman is ill. Iron deficiency is a stage that precedes iron-deficiency anemia, and most women below the ferritin threshold are not yet anemic; the fatigue, cold intolerance, and foggy concentration it produces are easy to attribute to almost anything else, which is exactly why it goes unnoticed. The threshold itself is contested — recent work argues the physiologically meaningful line for non-pregnant women sits closer to 25 µg/L, which would make the problem larger, not smaller. What is not seriously disputed is the shape of it: a common, recurring, under-recognized shortfall that tracks menstruation and pregnancy, hiding in plain sight behind the catch-all of being tired.
Related tidbits
About 25% of US women aged 12-49 are iron deficient at any given time (serum ferritin <15 µg/L, NHANES). Plant iron is absorbed at roughly a third the rate of meat's, so cutting out meat is one of the factors that moves this number.
Claim ledger
Every number below is what each source reported, with the verbatim quote we relied on and how we arrived at our figure. Click any link to verify directly.
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[1] Office of Disease Prevention and Health Promotion (Healthy People 2030), U.S. HHS — Reduce iron deficiency in females aged 12 to 49 years — NWS-17, Data Methodology
Reduce iron deficiency in females aged 12 to 49 years — NWS-17, Data Methodology- Statistic
Baseline: 25.5% of females aged 12-49 had iron deficiency in 2015-2016; national target 21.7%. Source: NHANES, CDC/NCHS.- Excerpt
“"Females 12 to 49 years are defined as having iron deficiency if they have a measurement of inflammation-adjusted serum ferritin less than 15µg/L." ”
- Source data from
- 2020-08-18
- Accessed
- 2026-07-18 · archived copy
- Calculation
- Healthy People 2030 objective NWS-17. Baseline 25.5% in 2015-2016, target 21.7%. Underlying data: National Health and Nutrition Examination Survey (NHANES), CDC/NCHS. The deficiency threshold is inflammation-adjusted serum ferritin <15 µg/L, adjusted for C-reactive protein using the BRINDA regression approach (a change from the Healthy People 2020 total-body-iron indicator). The 25.5% figure feeds both the native prevalence and the normalized headline directly (0.255), un-inflated; the cumulative-over-reproductive-years effect is carried in the upper uncertainty bound rather than the point estimate.
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[2] NIH Office of Dietary Supplements — Iron — Health Professional Fact Sheet
Iron — Health Professional Fact Sheet- Statistic
Pregnant women, women with heavy menstrual bleeding, and frequent blood donors are named among the groups more likely to have inadequate iron intakes / higher risk of iron deficiency.- Excerpt
“"Certain groups of people are more likely than others to have inadequate iron intakes, including pregnant women, infants and young children, women with heavy menstrual bleeding, and frequent blood donors. People with certain conditions, such as cancer, gastrointestinal disorders, and heart failure, may also have inadequate iron intakes." ”
- Source data from
- 2025-09-04
- Accessed
- 2026-07-18 · archived copy
- Calculation
- The NIH ODS fact sheet grounds the risk-group breakdown that feeds the personal_factor_multipliers (heavy menstrual bleeding, pregnancy, blood donation, vegetarian diet). It also supplies the measurement caveat: hemoglobin and hematocrit are insensitive screens, and serum ferritin — the marker used by Healthy People 2030 — is confounded by inflammation, which is why the CDC uses CRP adjustment. It does not itself state the 25.5% headline figure; that comes from the Healthy People 2030 / NHANES source above.
- Independence
- NIH ODS is editorially independent of the ODPHP Healthy People objective; both draw on NHANES but are separately authored government references.
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[3] PLOS ONE (Mei, Cogswell, et al.) — Iron Status and Reproduction in US Women: National Health and Nutrition Examination Survey, 1999-2006
Iron Status and Reproduction in US Women: National Health and Nutrition Examination Survey, 1999-2006- Statistic
Iron deficiency 9.8% in non-pregnant women vs 25.4% in pregnant women (NHANES 1999-2006), by a 2-of-3 biomarker definition.- Excerpt
“"rates of iron deficiency were 9.8% in non-pregnant women and 25.4% in pregnant women." ”
- Source data from
- 2014-11-13
- Accessed
- 2026-07-18 · archived copy
- Calculation
- NHANES 1999-2006. Iron deficiency defined as two of three of hemoglobin, serum ferritin (<12 ng/mL), and transferrin saturation (<16%) below cutoff — a stricter, older definition than the single-ferritin<15 threshold used by Healthy People 2030, which is why its non-pregnant figure (9.8%) is lower than the 25.5% headline. The pregnant-vs-non-pregnant contrast (25.4% vs 9.8%, a ~2.6x ratio) grounds the pregnancy multiplier and the cumulative-lifetime adjustment: even by the conservative definition, pregnancy alone lifts point prevalence to a quarter.
- Independence
- Peer-reviewed NHANES analysis, independent of the government fact sheets though built on overlapping survey cycles.