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Primary Care

Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomised placebo controlled trial

BMJ 2003; 326 doi: (Published 22 May 2003) Cite this as: BMJ 2003;326:1124
  1. F Verdon, general practitioner1,
  2. B Burnand, senior lecturer2,
  3. C-L Fallab Stubi, pharmacist3,
  4. C Bonard, general practitioner1,
  5. M Graff, general practitioner1,
  6. A Michaud, general practitioner1,
  7. T Bischoff, general practitioner1,
  8. M de Vevey, general practitioner1,
  9. J-P Studer, general practitioner1,
  10. L Herzig, general practitioner1,
  11. C Chapuis, general practitioner1,
  12. J Tissot, general practitioner1,
  13. A Pécoud, professor3,
  14. B Favrat, consultant of internal medicine3 (bernard.favrat{at}
  1. 1 General Practice Unit, University of Lausanne, rue du Bugnon 44, 1011 Lausanne, Switzerland
  2. 2 Health Care Evaluation Unit, Institute of Social and Preventive Medicine, University of Lausanne
  3. 3 Medical Outpatient Clinic, University of Lausanne
  1. Correspondence to: B Favrat
  • Accepted 20 March 2003


Objective To determine the subjective response to iron therapy in non-anaemic women with unexplained fatigue.

Design Double blind randomised placebo controlled trial.

Setting Academic primary care centre and eight general practices in western Switzerland.

Participants 144 women aged 18 to 55, assigned to either oral ferrous sulphate (80 mg/day of elemental iron daily; n=75) or placebo (n=69) for four weeks.

Main outcome measures Level of fatigue, measured by a 10 point visual analogue scale.

Results 136 (94%) women completed the study. Most had a low serum ferritin concentration; ≤ 20 μg/l in 69 (51%) women. Mean age, haemoglobin concentration, serum ferritin concentration, level of fatigue, depression, and anxiety were similar in both groups at baseline. Both groups were also similar for compliance and dropout rates. The level of fatigue after one month decreased by −1.82/6.37 points (29%) in the iron group compared with −0.85/6.46 points (13%) in the placebo group (difference 0.95 points, 95% confidence interval 0.32 to 1.62; P=0.004). Subgroups analysis showed that only women with ferritin concentrations ≤ 50 μg/l improved with oral supplementation.

Conclusion Non-anaemic women with unexplained fatigue may benefit from iron supplementation. The effect may be restricted to women with low or borderline serum ferritin concentrations.


  • Funding This study was sponsored by Robapharm. The sponsor was not involved in the analysis of the results nor in writing or correcting the manuscript.

  • Competing interests FV and BF received financial support from Robapharm for producing a preliminary report of the study.

  • Ethical approval: The study was approved by the ethical review committee for clinical research of the Department of Internal Medicine, University of Lausanne.

  • Accepted 20 March 2003
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