Health Reference LibraryFerritin 11: what your result means
This entry is part of the Nutri Tailor Health Reference Library — cited research on supplements, nutrients and adjacent areas of health.
Summary
Ferritin 11 µg/L means iron stores are close to exhausted. It sits beneath the WHO deficiency threshold of 15 and far below the UK practice line of 30, so every guideline reads this band as iron deficiency, whether or not haemoglobin has fallen yet. Symptoms are usual rather than exceptional here. The response has two equal halves: a GP conversation about the cause, and structured repletion with iron plus vitamin C, retested at 8 to 12 weeks.
Free iron and ferritin result interpreter
Enter what you have. Your ferritin alone works; the other fields sharpen the reading. Nothing you enter leaves this device. Nothing is saved. No AI is used, only published UK guideline thresholds.
This tool gives educational interpretation of published evidence. It is not personal dosing advice and it does not diagnose. It knows nothing about your history, symptoms or other results. Interpreting your results over time, alongside everything else about you, is what Nutri365 does.
How it works
Serum ferritin tracks stored iron, and single digits into the low teens mean the store is nearly gone. The body defends circulating haemoglobin for as long as it can by spending the reserve, which is why a result of 10 can coexist with a technically normal blood count; the buffer that made that possible is what has run out. From here, iron-dependent processes beyond red cells, energy metabolism, thyroid conversion, neurotransmitter synthesis, start feeling the shortage, which is why symptoms at 10 usually pre-date anaemia.
Guideline positions
WHO 2020 places iron deficiency in apparently healthy adults at ferritin below 15 µg/L, and a result of 11 sits 4 under that line. UK NICE-aligned practice confirms deficiency below 30 µg/L, a threshold with 92 percent sensitivity and 98 percent specificity, and NHS Scotland guidance notes below 40 is 98 percent on both, so 11 sits 19 below the UK confirmation threshold. Inflammation only pushes ferritin upward, so it cannot explain a result this low; even the WHO inflammation-adjusted ceiling of 70 reads 11 as deficient several times over.
Practical framework
A ferritin of 11 µg/L sits 4 under the WHO line of 15 and 19 under the UK threshold of 30, so stores are close to exhausted and every guideline reads this as iron deficiency, whether or not haemoglobin has fallen yet.
Cause first, and at this level that means a GP appointment booked this week, with red-flag symptoms making it urgent. Correction runs alongside once the GP is engaged: iron-rich food built into every day, and a supplement doing the heavy lifting, since food alone rebuilds single-digit stores impractically slowly. Iron & Vitamin C provides the absorption pairing in one product, alternate-day dosing per NHS guidance. Expect the haemoglobin check at 4 weeks if your GP arranges one, the ferritin retest at 8 to 12 weeks, and iron continuing roughly 3 months beyond feeling well. The repletion timeline entry maps what resolves when. For readers who decide on a supplement, Nutri Tailor stocks Iron & Vitamin C in the UK. To check your own result against the UK ranges, the Nutri Tailor free blood test result interpreter reads ferritin and the iron panel, vitamin D, B12 and folate. The Ferritin 10: what does a result under 12 mean? entry covers this band of results in full.
Sources
- 2020. WHO guideline on use of ferritin concentrations to assess iron status. World Health Organization.
- 2024. Iron deficiency guidelines. NHS Scotland Right Decisions.
- 2023. Ferritin interpretation, a guide for GPs. Royal United Hospitals NHS (NICE CKS aligned).