Key findings from detailed records
In a 12-week trial, 80 mg/day elemental iron reduced fatigue more than placebo in 198 menstruating women with low iron stores but without anemia. The finding supports assessing iron status when investigating fatigue; it is not a routine dose for people with adequate iron.
KNOWLEDGE RECORD
- Category
- Vitamins and minerals
- Last Reviewed
Names and related search termsIron / Iron / Elemental iron / Iron
Study type: human intervention study.
OUTCOME-SPECIFIC EVIDENCE
Scientific Evidence Profile
Assessment pending
An outcome-specific assessment has not yet been completed. This is not a finding that the ingredient is ineffective. The study records below remain available.
This profile concerns the stated outcome and population, not the ingredient as a whole. It is not a probability of benefit, a safety rating, a product efficacy rating or an indication of product adoption.
How we assess evidenceIngredient Profile
- What is it, and where is it found?
- Iron is an essential mineral. Foods supply heme and nonheme iron; the form and the rest of the meal influence absorption. [1]
Sources for this profile
Compound properties and formulation properties are different. These sources do not establish the efficacy of a finished supplement.
- NIH Office of Dietary Supplements — Iron Nutrient identity and food-source reference. Published by NIH Office of Dietary Supplements. Reference synthesis; not an individual clinical trial.
Profile sources checked:
Read the evidence in context
- Evidence: what was measured in the stated population or experimental model.
- Inference: an interpretation connecting findings; its applicability depends on the study conditions.
- Hypothesis: a proposed explanation or effect that remains to be tested.
Why It Matters #
Can fatigue change in people with low iron stores but no anemia? Check the detailed records for study conditions and use the literature map to compare other populations and outcomes.
What Was Studied #
198 menstruating women aged 18–53 with fatigue, ferritin below 50 µg/L and Hb above 12 g/dL. Randomized placebo-controlled trial. Outcomes: Fatigue score[1]
What Was Found #
Fatigue scores fell by 47.7% with iron and 28.8% with placebo. The between-group difference was significant, but differences in quality of life, depression and anxiety were not.[1]
What the Evidence Means #
Findings in women selected by iron status. They do not support supplementation for all fatigue or for people with adequate iron.[1]
Comparing similar populations, formulations, durations and outcomes helps identify where findings agree and where they differ.
What We Can Learn #
Do not increase iron on your own solely because of fatigue; first investigate iron status and its cause.
What Remains Unknown #
Further questions include reproducibility across populations and formulations, and the long-term balance of benefits and harms. Use the literature map as a starting point for these questions.
LITERATURE MAP / 10 PAPERS
Compare papers by conditions and findings.
A literature map covering different populations, outcomes and formulations. Read alongside detailed records to avoid treating one trial as the conclusion for an entire ingredient.
Selected: 2026-09-21. Bibliographic information checked against Europe PMC / PubMed. Editorial selection considered major papers and a range of populations and questions. This is not a systematic search covering all recent research.
10 RECORDS
A dash marks fields outside the bibliographic record. Use detailed records to compare findings and design records to connect mechanisms.
No papers match. Change the search conditions.
The literature map is an index of research questions and references. Individual assessment of results, doses, funding and COI is limited to the detailed study records. Related reports from the same trial may be included; paper counts are not counts of independent trials.
Explore the research Study Records
Listed doses describe study conditions, not recommended intake.
Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial.
PubMed 22777991DOI: 10.1503/cmaj.110950
- Authors
- Vaucher P, Druais PL, Waldvogel S, Favrat B.
- Journal
- CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne
- Publication year
- 2012
- Study design
- Randomized placebo-controlled trial
- Participants
- 198 menstruating women aged 18–53 with fatigue, ferritin below 50 µg/L and Hb above 12 g/dL.
- Dose and intervention
- 80 mg/day of elemental iron as ferrous sulfate
- Duration
- 12 weeks
- Outcomes and their role in the study
- Fatigue score
- Findings
- Fatigue scores fell by 47.7% with iron and 28.8% with placebo. The between-group difference was significant, but differences in quality of life, depression and anxiety were not.
- Limitations
- Findings in women selected by iron status. They do not support supplementation for all fatigue or for people with adequate iron.
- Funding
- Pierre Fabre Médicament sponsored and funded the study, designed it and managed data collection. The authors reported independent analysis and interpretation; academic authors were supported by their institutions.
- Conflict of Interest
- Favrat, Vaucher and Waldvogel disclosed Robapharm/Pierre Fabre research support. Favrat also disclosed Vifor/Pierre Fabre grants, lectures, expert testimony and an advisory meeting role; Druais disclosed Pierre Fabre consulting fees.
- Scope of source review
- The original abstract was checked for population, dose, duration and results; available source disclosures were checked separately. Any unverified disclosure details remain identified above.
Cite this page
LÍFSVARÐA. Iron: Can fatigue change in people with low iron stores but no anemia? Version 1.1 / Updated 2026-10-24
https://lifsvarda.com/knowledge/iron/Edited by LÍFSVARÐA (product brand).Editorial policy
Safety and interactions
Iron supplementation should be guided by iron status and the cause of deficiency, rather than fatigue alone. People with hereditary hemochromatosis should avoid iron supplements. Excess iron can cause gastrointestinal symptoms and serious poisoning; keep products out of children’s reach. Iron can reduce the absorption of levothyroxine and levodopa. Ask a clinician or pharmacist about concurrent medicines.
Safety section reviewed: 2026-10-24.
Sources and updates
- Vaucher P, Druais PL, Waldvogel S, Favrat B. (2012). Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial.The original abstract was checked for population, dose, duration and results; available source disclosures were checked separately. Any unverified disclosure details remain identified above.
First published: 2026-09-21 / Version 1.1. Updated 2026-09-23: Added a research comparison table and links to design records. Source notes identify the scope of verification when the full paper has not been reviewed. Research summaries and LÍFSVARÐA’s interpretation are distinguished.