Health Reference Library

Iron deficiency symptoms: what to check and what to do (UK)

This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.

Summary

Iron deficiency shows up as tiredness, breathlessness on effort, pale skin, hair shedding, brittle nails, restless legs, cold hands and feet, and sometimes cravings for ice. It is confirmed by two tests: ferritin, where below 30 micrograms per litre is deficiency under UK guidance, and a full blood count, which shows whether it has become anaemia. In women of reproductive age the cause is usually periods; in everyone else UK guidance sends the cause to the GP before the supplement. Iron deficiency without anaemia is real and worth correcting.

How it works

Iron is absorbed in the upper small intestine, carried on transferrin and stored as ferritin, and most of it sits inside red blood cells carrying oxygen. When intake or absorption falls behind loss, stores empty first (low ferritin with normal haemoglobin), then red cells become small and pale (low MCV), and finally haemoglobin falls and anaemia appears. Symptoms arrive at the first stage for many people, which is why a normal haemoglobin does not rule iron deficiency out.

Special populations

In women of reproductive age the cause is usually periods. In men and post-menopausal women, UK guidance sends the cause to the GP before the supplement. In pregnancy the thresholds differ; see iron in pregnancy.

Guideline positions

Two tests settle it: ferritin with CRP, because inflammation hides low iron, and a full blood count for haemoglobin and MCV. Ferritin below 30 micrograms per litre is deficiency under UK guidance. Transferrin saturation helps when ferritin is borderline, covered in the full iron panel. If the panel looks normal and you are still exhausted, iron panel normal but still exhausted sets out what to check.

Practical framework

Read the results with the free blood test result interpreter and the ferritin guide. If ferritin is under 30, a GP conversation about the cause comes first, then repletion with the form that suits you over the timeline in how long does iron take. Vitamin C with the iron dose increases absorption; tea, coffee and calcium at the same time reduce it. Retest at eight weeks for haemoglobin and at three to six months for stores. Nutri Tailor stocks iron bisglycinate with vitamin C.

Sources

  1. Snook J, Bhala N, Beales ILP, Cannings D, Kightley C, Logan RPH, Pritchard DM, Sidhu R, Surgenor S, Thomas W, Verma AM 2021. British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. Gut. PMID: 34497146 · DOI: 10.1136/gutjnl-2021-325210
  2. NICE Clinical Knowledge Summary (CKS, UK government). Anaemia - iron deficiency. NICE Clinical Knowledge Summaries (CKS).
  3. World Health Organization 2020. WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations. World Health Organization (WHO).
  4. Camaschella C 2015. Iron-deficiency anemia. New England Journal of Medicine. PMID: 25946282 · DOI: 10.1056/nejmra1401038
  5. Ganz T 2019. Anemia of inflammation. New England Journal of Medicine. PMID: 31532961 · DOI: 10.1056/nejmra1804281
  6. Verdon F, Burnand B, Stubi CL, Bonard C, Graff M, Michaud A, Bischoff T, de Vevey M, Studer JP, Herzig L, Chapuis C, Tissot J, Pécoud A, Favrat B 2003. Iron supplementation for unexplained fatigue in non-anaemic women: double blind randomised placebo controlled trial. BMJ. PMID: 12763985 · DOI: 10.1136/bmj.326.7399.1124
  7. Vaucher P, Druais P-L, Waldvogel S, Favrat B 2012. Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. CMAJ. PMID: 22777991 · DOI: 10.1503/cmaj.110950
  8. Krayenbuehl PA, Battegay E, Breymann C, Furrer J, Schulthess G 2011. Intravenous iron for the treatment of fatigue in nonanemic, premenopausal women with low serum ferritin concentration. Blood. PMID: 21705493 · DOI: 10.1182/blood-2011-04-346304
  9. Keller P, von Kanel R, Hincapie CA, et al 2020. The effects of intravenous iron supplementation on fatigue and general health in non-anemic blood donors with iron deficiency: a randomized placebo-controlled superiority trial. Scientific Reports. PMID: 32848185 · DOI: 10.1038/s41598-020-71048-0
  10. Dugan C, Cabolis K, Miles LF, Richards T 2022. Systematic review and meta-analysis of intravenous iron therapy for adults with non-anaemic iron deficiency: An abridged Cochrane review. Journal of Cachexia, Sarcopenia and Muscle. PMID: 36321348 · DOI: 10.1002/jcsm.13114
  11. Murray-Kolb LE, Beard JL 2007. Iron treatment normalizes cognitive functioning in young women. American Journal of Clinical Nutrition. PMID: 17344500 · DOI: 10.1093/ajcn/85.3.778
  12. Stabler SP 2013. Vitamin B12 deficiency. New England Journal of Medicine. PMID: 23301732 · DOI: 10.1056/nejmcp1113996
  13. Houston BL, Hurrie D, Graham J, et al 2018. Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review of randomised controlled trials. BMJ Open. PMID: 29626044 · DOI: 10.1136/bmjopen-2017-019240

Related entries

Back to Iron overview