Infant Iron Deficiency and Iron Supplementation Predict Adolescent Internalizing, Externalizing, and Social Problems

Area of Science:

• Child and Adolescent Psychology
• Nutritional Science
• Developmental Pediatrics

Background:

• Iron deficiency in infancy is a global health concern.
• Early life nutrition significantly impacts long-term neurodevelopment.
• Behavioral and social problems in adolescence have complex etiologies.

Purpose of the Study:

• To investigate the association between infant iron status and adolescent behavioral outcomes.
• To examine the long-term effects of early iron supplementation versus iron deficiency.
• To identify specific behavioral domains affected by infant iron status.

Main Methods:

• Longitudinal follow-up study of adolescents from Santiago, Chile.
• Inclusion of participants from a preventive iron supplementation trial.
• Assessment of infant iron status at 12 and 18 months.
• Adolescent and parent-reported behavioral assessments (Youth Self Report, Child Behavior Checklist) at 11-17 years.

Main Results:

• Infant iron supplementation was associated with higher self-reported ADHD but lower parent-reported conduct disorder.
• Iron deficiency (with or without anemia) in infancy predicted increased adolescent internalizing (anxiety), externalizing (ADHD, conduct, aggression), and social problems.
• Iron sufficiency in infancy was linked to fewer behavioral problems in adolescence.

Conclusions:

• Infant iron deficiency, with or without anemia, is a significant risk factor for internalizing, externalizing, and social problems in adolescence.
• Maintaining iron sufficiency in infancy is crucial for preventing long-term behavioral issues.
• Findings highlight the critical role of early iron status in adolescent mental health.