Higher Body Mass Index Is Associated with Iron Deficiency in Children 1 to 3 Years of Age

J Pediatr. 2019 Apr;207:198-204.e1. doi: 10.1016/j.jpeds.2018.11.035. Epub 2019 Jan 7.


Objectives: To examine the association between body mass index (BMI) and iron deficiency in early childhood, while considering the influence of low-grade systemic inflammation.

Study design: Healthy children ages 1-3 years were included in a cross-sectional analysis. Age- and sex-standardized World Health Organization BMI z score (zBMI) was calculated using height/length and weight measurements; iron status was assessed by serum ferritin; inflammation was assessed by C-reactive protein (CRP). Children with CRP ≥10 mg/L were excluded because this may indicate acute systemic inflammation. Adjusted multivariable regression analyses were used to investigate the association between zBMI and both serum ferritin (µg/L), and iron deficiency (serum ferritin <12 µg/L). We performed prespecified subgroup analyses according to CRP level (normal [≤1.0 mg/L] and low-grade inflammation [>1.0 mg/L to <10.0 mg/L]).

Results: Of 1607 children included, 20% were categorized as with zBMI >1, 13% had iron deficiency, and 18% had low-grade inflammation. Higher zBMI was associated with lower serum ferritin (-1.51 µg/L, 95% CI -2.23, -0.76, P < .0001) and increased odds of iron deficiency (OR 1.28, 95% CI 1.10, 1.50, P = .002). Though there was no interaction between zBMI and CRP for the adjusted linear regression model (P = .79) or logistic regression model (P = .43), children with low-grade inflammation had a higher serum ferritin (P < .0001).

Conclusions: Higher zBMI is associated with increased risk for iron deficiency in children between 1 and 3 years, and should be considered as a risk factor in targeted screening. Further research is needed to better understand the relationship between serum ferritin and CRP for children in all weight categories.

Trial registration: ClinicalTrials.gov: NCT01869530.

Keywords: C-reactive protein; body mass index; early childhood; iron deficiency; serum ferritin.

Publication types

  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Anemia, Iron-Deficiency / blood
  • Anemia, Iron-Deficiency / epidemiology
  • Anemia, Iron-Deficiency / etiology*
  • Biomarkers / blood
  • Body Mass Index*
  • C-Reactive Protein / metabolism*
  • Canada / epidemiology
  • Child, Preschool
  • Cross-Sectional Studies
  • Disease Progression
  • Female
  • Ferritins / blood
  • Follow-Up Studies
  • Humans
  • Incidence
  • Infant
  • Inflammation / blood*
  • Iron / blood*
  • Male
  • Retrospective Studies
  • Risk Assessment / methods*
  • Risk Factors


  • Biomarkers
  • C-Reactive Protein
  • Ferritins
  • Iron

Associated data

  • ClinicalTrials.gov/NCT01869530

Grant support