High Prevalence of Poor Iron Status Among 8- to 16-Year-Old Youth Athletes: Interactions Among Biomarkers of Iron, Dietary Intakes, and Biological Maturity

Abstract

Objective: The purpose of this study was to determine the prevalence of poor iron status in young athletes throughout the stages of iron deficiency and assess sex differences with iron deficiency in relation to growth and development and dietary intake.

Methods: A cross-sectional analysis evaluated young male and female athletes (n = 91) between the ages 8 and 16 years. Anthropometric assessments, body composition, dietary intakes, and blood samples measuring ferritin, soluble transferrin receptor (sTfR), and hemoglobin (Hb) were examined. Prevalence was calculated as percentages, and independent samples t tests examined sex differences. Pearson product-moment correlation coefficient analyses quantified relationships among variables for the composite sample and each sex separately.

Results: Iron depletion (low ferritin) was present in 65% and 86%, low iron levels (sTfR) in 51% and 68%, and anemia (low Hb) in 46% and 53% of the males and females, respectively. As iron deficiency progressed from low ferritin to high sTfR to anemia, prevalence decreased in both sexes, but always remained higher in females. Males were greater than females for weight, arm muscle size, and ferritin concentrations, while females were greater than males for biological maturity (p ≤ 0.05). Dietary iron intake was moderately to highly correlated (r = 0.543–0.723, p ≤ 0.05) with growth and development in females, but not males.

Conclusions: Prevalence of poor iron status was higher than expected, particularly in adolescent females. Since rapid growth combined with sports participation may create high demands for iron bioavailability, emphasis may need to be placed on dietary iron intake for young athletes, particularly females.

Keywords:

• Iron deficiency
• adolescent athletes
• children
• dietary iron
• sports nutrition

Acknowledgments

We thank all study participants and research staff for their help in data collection.

Disclosure statement

All authors have declared no competing interests or financial interests regarding this study. Data can be made available upon reasonable request to the corresponding author.

Additional information

Funding

Efforts for this study were funded, in part, by the Nebraska Beef Council and the University of Nebraska Agriculture Research Division with funds provided by the Hatch Act (Agency: U.S. Department of Agriculture, National Institute of Food and Agriculture; Accession No: 1000080; Project No: NEB-36-078) and a grant from Abbott Nutrition, Columbus, OH.