Trends in Anemia and Iron Deficiency Among Nonpregnant U.S. Women of Reproductive Age, 1999-2023.
Level 4 - case-series / case-control
Serial cross-sectional study using national survey data (NHANES).
PubMed 41926767 · doi:10.1097/AOG.0000000000006277
What was done
In a serial cross-sectional analysis of National Health and Nutrition Examination Survey (NHANES) data from 1999–2000 through 2021–2023, 8,200 nonpregnant US women aged 20–45 years were evaluated. Hemoglobin and serum ferritin measurements were used to track temporal trends in anemia (hemoglobin < 12.0 g/dL), iron deficiency (serum ferritin < 15.0 µg/L), and iron deficiency anemia (IDA, both criteria met). Odds of each condition per NHANES survey cycle were estimated using adjusted logistic regression models.
What was found
Across all cycles combined, overall weighted US prevalence was 9.8% (95% CI, 9.0–10.7%) for anemia, 17.3% (95% CI, 16.4–18.3%) for iron deficiency, and 6.2% (95% CI, 5.5–6.8%) for IDA. Between 1999–2000 and 2021–2023, anemia prevalence rose from 8.0% (95% CI, 5.8–10.9%) to 14.2% (95% CI, 11.8–17.1%), while IDA prevalence rose from 4.3% (95% CI, 3.2–6.0%) to 9.1% (95% CI, 7.3–11.4%). Iron deficiency prevalence remained high with a modest change from 17.9% (95% CI, 16.4–19.5%) to 18.8% (95% CI, 16.1–21.9%). In adjusted models, the odds of both anemia and IDA increased by approximately 8% per survey cycle (anemia: aOR 1.08, 95% CI, 1.05–1.11; IDA: aOR 1.08, 95% CI, 1.04–1.12).
Why it matters
These data demonstrate a substantial long-term increase in anemia and IDA among nonpregnant women of reproductive age in the United States over the past two decades. The findings provide population-level evidence that may inform clinical screening policies and public health nutritional interventions.
Limits
The study design is cross-sectional, precluding longitudinal follow-up or causal inferences regarding drivers of the rising trends. Iron deficiency was assessed using a single ferritin cutoff (<15.0 µg/L) without reported adjustment for acute or chronic inflammation, which can falsely elevate ferritin levels and underestimate deficiency. The abstract does not detail underlying causes for non-iron anemias or assess dietary intake and supplementation patterns.
Cited by
- supports Approximately 16% of menstruating women are iron deficient.