Is Iron Treatment Beneficial In, Iron-Deficient but Non-Anaemic (IDNA) Endurance Athletes? A Systematic Review and Meta-Analysis

Br J Sports Med. 2015 Nov;49(21):1389-97. doi: 10.1136/bjsports-2014-093624. Epub 2014 Oct 31.

Abstract

Purpose: The aim of this study was to determine whether iron treatments improve the iron status and aerobic capacity of iron deficient non-anaemic endurance athletes.

Method: A meta-analysis of studies that investigated the effects of iron treatment on serum ferritin (sFer), serum iron (sFe), transferrin saturation (Tsat), haemoglobin concentration ([Hb]) and (VO(2max)). Seventeen eligible studies were identified from online databases.

Results: Analysis of pooled data indicated that iron treatments had a large effect on improving sFer (Hedges' g=1.088, 95% CI 0.914 to 1.263, p<0.001), sFe (Hedges' g=1.004, 95% CI 0.828 to 1.181, p<0.001) and Tsat (Hedges g=0.741, 95% CI 0.564 to 0.919, p<0.001) and a moderate effect on improving [Hb] (Hedges' g=0.695, 95% CI 0.533 to 0.836, p<0.001) and (VO(2max)) (Hedges' g=0.610, 95% CI 0.399 to 0.821, p<0.001). Regression analysis revealed a significant interaction between the effect of iron treatment on sFer and treatment duration, suggesting treatments that lasted beyond 80 days appear to have the least effect on sFer.

Conclusions: These results indicate iron treatments improve the iron status and aerobic capacity of iron deficient non-anaemic endurance athletes.

Keywords: Aerobic fitness; Anaemia; Endurance; Iron metabolism; Running.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Athletic Performance / physiology
  • Drug Administration Routes
  • Female
  • Hemoglobins / metabolism
  • Humans
  • Iron / administration & dosage
  • Iron / deficiency*
  • Male
  • Physical Endurance / physiology*
  • Regression Analysis
  • Treatment Outcome

Substances

  • Hemoglobins
  • Iron