Health Reference LibraryFerritin 19: 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
By UK standards, yes, ferritin 19 µg/L is low. NICE-aligned practice reads anything below 30 as confirming iron deficiency, a threshold with 92 percent sensitivity and 98 percent specificity, and below 40 is 98 percent both. The WHO line of 15 is stricter, which is why 19 often escapes a lab flag, but stores at 19 are thin enough to produce tiredness and under-par training long before anaemia. Reasonable response: iron-focused food plus a supplement, cause considered, ferritin 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
Ferritin reads the iron reserve, and the 16 to 20 band is where the reserve is thin without being empty. Stores here still buffer haemoglobin, which is why blood counts usually look fine, but the margin is small: a heavy period cycle, a training block, a stomach bug that dents appetite, and the buffer is gone. This is also the band where lab reference ranges mislead most, because a range starting at 12 or 15 prints 18 as normal while the clinical evidence reads it as deficient.
Guideline positions
WHO 2020 places iron deficiency in apparently healthy adults at ferritin below 15 µg/L, and a result of 19 clears that line by 4, which is why many UK reports print it without a flag. 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 19 sits 11 below the UK confirmation threshold, and the UK threshold is the one your GP works to. A CRP alongside makes the number trustworthy, because inflammation raises ferritin and a raised CRP means true stores may be lower still.
Practical framework
A ferritin of 19 µg/L clears the WHO line of 15 by 4 and misses the UK confirmation threshold of 30 by 11, which is why a UK report may print it without a flag while NICE-aligned practice reads it as iron deficiency.
This band rewards acting early, before the slide into the low teens. Food first and genuinely: red meat or legumes daily, vitamin C alongside plant iron, tea and coffee away from iron meals. A supplement makes the arithmetic work, and Iron & Vitamin C pairs the two absorption partners, alternate days per NHS guidance. The cause deserves a thought even where no GP visit feels needed: periods, training load, diet pattern, and any gut symptoms. Retest at 8 to 12 weeks aiming to see the number climb toward and past 30; the repletion timeline shows the realistic pace. 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 18: is that low or normal? 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).