Research paper
Effect of iron intake on iron status: a systematic review and meta-analysis of randomized controlled trials.
Study answer
What this study found
Iron supplementation improved iron-status biomarkers overall, but effects were heterogeneous across trials. Pooled effects favored iron for hemoglobin (MD +0.51 g/dL; 95% CI 0.37, 0.65; P < 0.00001; I2 = 83%), serum ferritin (MD 9.19 mg/L; 95% CI 6.63, 11.75; P < 0.00001; I2 = 73%), soluble transferrin receptor (MD 20.46 mg/L; 95% CI 20.68, 20.23; P = 0.0001; I2 = 75%), and body iron (MD 1.89 mg/kg; 95% CI 1.04, 2.75; P = 0.0001; I2 = 60%). Baseline ferritin modified hemoglobin response, with a 0.08-g/dL increase in response per 10-mg/L higher baseline ferritin (P = 0.02). The review…
- Study & population
- Systematic review and meta-analysis of 41 randomized controlled trials in healthy adults, reported in 43 articles.
- Intervention
- Across 41 randomized controlled trials, active arms received supplemental iron in a wide range of formulations and delivery vehicles, including ferrous sulfate, ferrous fumarate, ferrous carbonate, heme iron, and iron-fortified foods or beverages.
- Key limitation
- Substantial heterogeneity was present for all major outcomes, and intervention regimens varied widely in dose, form, frequency, and duration.
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Open PDFOriginal abstract
BACKGROUND The response of status biomarkers to an increase in iron supply depends on several physiologic and environmental factors, which make it difficult to predict the outcome of an intervention. OBJECTIVE We assessed effects of baseline iron sta…