Lab marker
Ferritin
Serum ferritin
The best single marker of body iron stores — low values precede anaemia by months.
What it measures
Ferritin is the major iron storage protein. Serum concentrations correlate with bone marrow iron stores in the absence of inflammation. Falls before haemoglobin in iron depletion; rises in iron overload and in inflammatory states (acute-phase reactant).
Reference context
3 guideline sources
Lab 'normal' ranges extend down to ~15 ng/mL, but symptomatic depletion is common in the 15–50 range — especially in women, athletes, and vegetarians. Conversely, persistently high ferritin (>300) without a known inflammatory cause warrants workup for haemochromatosis.
Population context — consult guideline targets below
Mechanism
Why moving this marker matters
Iron is required for oxygen transport, mitochondrial function, neurotransmitter synthesis, and immune function. Depletion causes fatigue, reduced exercise capacity, restless legs, and impaired cognitive function before frank anaemia appears.
Guideline targets
What major guidelines recommend
WHO 2020 (deficiency, adults)
<30 ng/mL
BSH 2021 (functional symptoms threshold)
<50 ng/mL — consider supplementation if symptomatic
Overload signal
>300 ng/mL (men) / >200 ng/mL (women) without acute illness — investigate
How to measure
The test, where to get it, when to repeat
Method
Standard blood draw. Pair with a CRP — ferritin is also an acute-phase reactant, so elevated values with elevated CRP do not reliably indicate iron overload.
Where
GP standard panel or private lab.
Typical cost
€10–20 private.
Fasting
Not required
When to test
BSH 2021
Test in adults with unexplained fatigue, reduced exercise capacity, restless legs, hair loss, or menstrual blood loss.
WHO 2020
Population-level screening in women of reproductive age in iron-deficient settings.
Where to test
Independent labs offering this test
Healicus refers you to independent laboratories. You order from the lab; they take the sample, run it, and return your result on their own platform. Healicus never sees your value.
Randox Health
UK · EU · INTLClinic-based premium panels — wider biomarker breadth than home-test brands.
Visit Randox Health
Synlab
DE · EU · INTLEurope-wide medical lab network — referrals via partner GPs and direct-to-consumer programmes where offered.
Visit Synlab
Cerascreen
DE · EUEstablished German home-test catalogue — ISO-certified labs, German-language reports.
Visit Cerascreen
Medichecks
UKUKAS-accredited home blood-test panels with GP-equivalent biomarker coverage.
Visit Medichecks
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Context
Reading the numbers
Lab 'normal' ranges extend down to ~15 ng/mL, but symptomatic depletion is common in the 15–50 range — especially in women, athletes, and vegetarians. Conversely, persistently high ferritin (>300) without a known inflammatory cause warrants workup for haemochromatosis.
Caveats
Inflammation, liver disease, recent transfusion, and recent intense exercise all raise ferritin independently of iron stores. Pair with CRP and transferrin saturation when interpretation matters clinically.
Practices
What's been shown to influence this marker
Adequate dietary heme + non-heme iron from fish, legumes, leafy greens, plus ascorbate-rich foods to enhance absorption. Maintains repletion in most adherent adults outside menstrual or GI-loss contexts.
Heavy alcohol is a recognised driver of iron accumulation (alcoholic siderosis). Reduction is first-line in elevated ferritin without clear inflammation.
Mediterranean dietary pattern
Habit·Olive oil, fish, nuts, legumes, plants. The most-studied diet for cardiovascular and cognitive longevity.
Why
The Mediterranean pattern — heavy on plants, olive oil, fish, nuts, legumes; moderate fish and dairy; light on red meat — has the strongest evidence base of any specific diet for long-term cardiovascular and cognitive outcomes. PREDIMED, the largest trial, showed ~30% reduction in major cardiovascular events vs. low-fat control.
Slot in your day
How to do it
How
Olive oil as the primary fat. Plants at every meal. Fish 2–3× per week. Nuts daily (small handful). Red meat once a week or less. Wine optional, with food.
Sticking with it
Stock the kitchen for one week's pattern. Decisions live in the shopping list, not at mealtime.
Markers this may influence
Evidence
Limit alcohol intake
Habit·Lancet pooled analysis (n=599,912): lowest mortality risk threshold is ~100 g/week — about 5-6 standard drinks total.
Why
Wood et al. 2018 Lancet combined individual-participant data from 83 prospective studies (n=599,912 current drinkers in 19 high-income countries). Above ~100 g/week (about 5-6 UK standard units), all-cause mortality climbs in a dose-response manner. Below that threshold the curve is roughly flat — there is no protective effect. Reductions from heavier intake to ≤100 g/week could add up to 2 years of life expectancy at age 40.
How to do it
How
Track intake honestly for one week. If above threshold, set a weekly cap rather than a daily one (avoids the 'I'll catch up' trap). Several alcohol-free days per week is the simplest pattern. Sleep quality typically improves within 1-2 weeks of reduced intake.
Ideal for
Anyone currently drinking above ~100 g/week (≈one bottle of wine, six pints of beer, or a half-bottle of spirits).
Markers this may influence
Evidence
Take to your physician
Worth discussing
- Whether your value is consistent with your symptoms and clinical context (especially in menstruating women, athletes, and vegetarians).
- If low, whether oral iron, dietary changes, or further workup (coeliac screen, GI loss workup) is appropriate.
- If persistently high without inflammation, haemochromatosis screening (HFE gene + transferrin saturation).
Sources
Cited literature
- [1]British Society for Haematology — UK guidelines on the management of iron deficiency in pregnancy and adults(2021)
- [2]WHO 2020 — Serum ferritin concentrations for the assessment of iron status in individuals and populations(2020)
- [3]European Haemochromatosis Reference Standard — diagnosis and management thresholds(2018)
Edited by Carl Pöhl, MD · Healicus editorial
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