Credits Earned (2024) Crédits obtenus

Redeem Prepaid Membership

Tools for Practice Outils pour la pratique

#79 Iron Supplementation in Non-Anemic Women with Unexplainable Fatigue: Another Tired Theory?

Is iron supplementation a reasonable option in treating non-anemic iron-deficient women with unexplained fatigue?

In female patients with iron deficiency without anemia who have unexplained fatigue, weak evidence suggests small benefit from iron supplementation. If real, about 1 in 4-10 may have improvement in fatigue.

CFPCLearn Logo

Reading Tools for Practice Article can earn you MainPro+ Credits

La lecture d'articles d'outils de pratique peut vous permettre de gagner des crédits MainPro+

Join Now S’inscrire maintenant

Already a CFPCLearn Member? Log in

Déjà abonné à CMFCApprendre? Ouvrir une session

Four randomized controlled trials (RCTs) of menstruating non-anemic women (mean age mid-30s) with unexplained fatigue 
  • 294 women with serum ferritin <50 µg/L,1 intravenous iron 1000 mg or placebo x1 dose, followed x8 weeks 
    • Iron statistically significantly improved fatigue score by 0.8 points versus placebo (22-point scale) 
      • More patients reported >50% improvement in their fatigue with iron: 33.3% versus 16.4% with placebo, number needed to treat (NNT)=6 
    • Adverse eventsIron 57.2% versus placebo 49% (p=0.16). 
  • 198 women with serum ferritin <50 µg/L,2 oral ferrous sulfate (80 mg elemental iron) or placebo daily x12 weeks 
    • Iron statistically significantly improved fatigue score by 3.5 points versus placebo (40-point scale) 
    • No significant effects on quality of life, depression or anxiety. 
    • Adverse events: Iron 34.3% versus placebo 25% (p=0.20). 
  • 144 women,3 oral ferrous sulfate (80 mg elemental iron) or placebo daily x4 weeks 
    • Iron statistically significantly improved fatigue score by 0.97 points versus placebo (10-point scale) 
    • In subgroup analysis, only benefit if serum ferritin <50 µg/L. 
  • 90 women with serum ferritin <50 µg/L,4 intravenous iron 200 mg or placebo x4 doses in 2 weeks, followed x12 weeks 
    • No statistically significant difference in fatigue score 
      • However, significantly more patients reported “slight or better improvement in fatigue” with iron on a different fatigue questionnaire 
        • Iron 63% versus placebo 34%, NNT=4 
    • Adverse events: Iron 53% versus placebo 66%. 
  • Interpretation is challenged by: 
    • Each study using multiple and differing scales 
    • High placebo response  
    • Small changes in scales with no validated minimal clinically important differences 
      • One study2 later5 provided the number of patients reaching cut-offs of uncertain relevance: None significant (if adequately powered, NNT might be ~10). 
  • Cost: Oral iron costs $20 for a year’s supply;6 one 1000-mg dose of intravenous iron costs ~$300-450.7 
aug 3 2016 Ricky Turgeon BSc(Pharm) ACPR PharmD

Latest Tools for Practice
Derniers outils pour la pratique

#370 Antibiotics or no antibiotics for acute diverticulitis, that is the question!

Do antibiotics change clinical outcomes for patients with acute uncomplicated diverticulitis?
Read Lire 0.25 credits available Crédits disponibles

#369 Remind me, do medications that target brain amyloid improve my dementia?

Are amyloid-targeting monoclonal antibodies safe and effective for mild cognitive impairment or Alzheimer’s dementia?
Read Lire 0.25 credits available Crédits disponibles

#368 Sodium Restriction in Heart Failure: Beneficial or pouring salt in the wound?

Does sodium restriction improve outcomes in patients with chronic heart failure?
Read Lire 0.25 credits available Crédits disponibles

This content is certified for MainPro+ Credits, log in to access

Ce contenu est certifié pour les crédits MainPro+, Ouvrir une session

  • Daniel McKennitt MD
  • G. Michael Allan MD CCFP

1. Favrat B, Balck K, Breymann C, et al. PLoS ONE 2014;9:e94217.

2. Vaucher P, Druais PL, Waldvogel S, et al. CMAJ 2012;184:1247-54.

3. Verdon F, Burnand B, Fallab Stubi CL, et al. BMJ 2003;326:1124–7.

4. Krayenbuehl PA, Battegay E, Breymann C, et al. Blood 2011;118:3222-7.

5. Vaucher P. Available at: Last accessed: Dec 6, 2016.

6. Nickonchuk T, Lee J, Allan GM, et al. Available at: Last accessed: Dec 6, 2016.

7. Therapeutics Initiative. Available at: intravenous-iv-iron-for-severe-iron-deficiency/ Last accessed: Dec 6, 2016.

Authors do not have any conflicts of interest to declare.

Les auteurs n’ont aucun conflit d’intérêts à déclarer.

Most recent review: 03/08/2016

By: Ricky Turgeon BSc(Pharm) ACPR PharmD


Evidence Updated: New trial; Context updated; Bottom Line: Minor change.

Learning at a glance
Yearly credits
Acquired ()
Your content by topic
Cardiology Dermatology Emergency
My Bookmarks