Overweight children have higher circulating hepcidin concentrations and lower iron status but have dietary iron intakes and bioavailability comparable with normal weight children

Int J Obes (Lond). 2009 Oct;33(10):1111-7. doi: 10.1038/ijo.2009.146. Epub 2009 Jul 28.


Background: Obesity increases the risk for iron deficiency, but the underlying mechanism is unclear. It is possible that overweight individuals may have lower dietary iron intake and/or bioavailability. Alternatively, obesity-related inflammation may increase hepcidin concentrations and reduce iron availability. Circulating hepcidin levels have not been compared in normal weight vs overweight individuals.

Objective: The objective of this study was to compare iron status, dietary iron intake and bioavailability, as well as circulating levels of hepcidin, leptin and interleukin-6 (IL-6), in overweight vs normal weight children.

Design: In 6-14-year-old normal and overweight children (n=121), we measured dietary iron intake, estimated iron bioavailability and determined body mass index s.d. scores (BMI-SDS). In all children (n=121), we measured fasting serum ferritin, soluble transferrin receptor (sTfR), C-reactive protein (CRP) and leptin; in a subsample, we measured IL-6 (n=68) and serum hepcidin (n=30).

Results: There were no significant differences in dietary iron intake or bioavailability comparing normal and overweight children. The prevalence of iron-deficient erythropoiesis (an increased sTfR concentration) was significantly higher in the overweight than in the normal weight children (20 vs 6%, P=0.022, with sTfR concentrations of 4.40+/-0.77 and 3.94+/-0.88 mg l(-1), respectively, P=0.010). Serum hepcidin levels were significantly higher in the overweight children (P=0.001). BMI-SDS significantly correlated with sTfR (P=0.009), serum hepcidin (P=0.005) and the three measures of subclinical inflammation, namely CRP (P<0.001), IL-6 (P<0.001) and leptin (P<0.001). In a multiple regression model, serum hepcidin was correlated with BMI-SDS (P=0.020) and body iron (P=0.029), but not with the inflammatory markers.

Conclusion: Our findings indicate that there is reduced iron availability for erythropoiesis in overweight children and that this is unlikely due to low dietary iron supply but rather due to hepcidin-mediated reduced iron absorption and/or increased iron sequestration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Antimicrobial Cationic Peptides / blood*
  • Biological Availability
  • Biomarkers / blood
  • C-Reactive Protein / metabolism*
  • Child
  • Diet
  • Erythropoiesis
  • Female
  • Hepcidins
  • Humans
  • Iron / blood*
  • Iron Deficiencies
  • Iron, Dietary / administration & dosage
  • Iron, Dietary / blood*
  • Iron, Dietary / pharmacokinetics
  • Leptin / blood*
  • Male
  • Obesity / blood*
  • Obesity / complications
  • Obesity / epidemiology
  • Reference Values
  • Switzerland / epidemiology
  • Transferrin / metabolism*


  • Antimicrobial Cationic Peptides
  • Biomarkers
  • HAMP protein, human
  • Hepcidins
  • Iron, Dietary
  • Leptin
  • Transferrin
  • C-Reactive Protein
  • Iron