Psychiatric and cognitive outcomes of iron supplementation in non-anemic children, adolescents, and menstruating adults: A meta-analysis and systematic review

source extracted confidence: high 2026-04-09
#humans #adolescent #dietary-supplements #child #adult

Psychiatric and cognitive outcomes of iron supplementation in non-anemic children, adolescents, and menstruating adults: A meta-analysis and systematic review

Fiani et al., 2025 | Neurosci Biobehav Rev | Meta Analysis

Citation

Fiani Dimitri, Chahine Sana, ... Calarge Chadi. Psychiatric and cognitive outcomes of iron supplementation in non-anemic children, adolescents, and menstruating adults: A meta-analysis and systematic review. Neurosci Biobehav Rev. 2025-Nov;178:106372. doi:10.1016/j.neubiorev.2025.106372

Abstract

Iron plays a key role in brain functions like energy metabolism and neurotransmitter synthesis. Yet, iron deficiency (ID) is the most common nutritional deficiency worldwide. Children, adolescents, and menstruating adults are particularly at risk. Even in the absence of anemia, ID can be associated with fatigue, reduced quality of life, and worsened symptoms of depression, anxiety, and ADHD. This systematic review and meta-analysis examined the impact of iron supplementation on psychiatric and cognitive outcomes in non-anemic children, adolescents, and menstruating adults. PubMed and Scopus searches identified randomized placebo-controlled trials (RCTs) and pre-post studies involving iron supplementation in non-anemic children and adolescents (ages 5-17 years) and menstruating adults. Studies of similar designs and outcomes were pooled for random-effects meta-analyses. Eighteen studies (12 RCTs, six pre-post) involving 1408 participants, including 1176 menstruating adults (mean age 34.6 ± 9.5 years) and 204 children and adolescents (mean age 13.9 ± 1.4 years, 56 % female), were identified, and sixteen were meta-analyzed. In RCTs, supplementation improved symptoms of anxiety (d = 0.34), fatigue (d = 0.34), physical well-being (d = 0.42), cognitive intelligence (d = 0.46), and short-term memory (d = 0.53) but not attention or depression. Pre-post studies showed improvements in depression (d = 0.93), fatigue (d = 1.01), and overall psychiatric symptoms (d = 1.13). Subgroup analyses confirmed consistent results for ID-only groups, youth, and menstruating adults, though supplementation effects were absent when excluding ID participants. This suggests that, before anemia emerges, ID may impact brain function, potentially requiring identification and treatment.

Key Findings

This suggests that, before anemia emerges, ID may impact brain function, potentially requiring identification and treatment.

Outcomes Measured

  • anxiety
  • depression

Population

Field Value
Population See abstract
Sample Size 1408
Age Range 5-17 years
Condition anxiety

MeSH Terms

  • Humans
  • Adolescent
  • Dietary Supplements
  • Child
  • Adult
  • Iron
  • Cognition
  • Anxiety

Evidence Classification

  • Level: Meta Analysis
  • Publication Types: Systematic Review, Journal Article, Meta-Analysis
  • Vertical: iron-cognition

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09