Monitoring iron levels and vitamin deficiencies from home is straightforward in the UK with a venous or fingerprick blood test reviewed by a GMC-registered doctor. A targeted panel such as the Blood Health 6 measures ferritin, iron, transferrin, transferrin saturation, active B12 and folate in a single sample — giving you a clear picture of the nutrients that drive red blood cell production, oxygen transport and energy. Results are usually available within 2 working days of the lab receiving the sample, and a doctor's analysis highlighting any out-of-range markers is included in the price. All Lola blood tests are for adults aged 18 and over.
This guide explains what each marker measures, what the UK reference ranges are, which test to choose, how collection works, and what to do with your results.
What iron and vitamin deficiency markers measure
Iron and iron storage
Iron (Fe) is the mineral your body uses to make haemoglobin, the protein in red blood cells that carries oxygen. Low iron can cause fatigue, weakness, shortness of breath or hair loss — even before symptoms are obvious. Iron is influenced by diet (red meat, leafy greens, fortified cereals), menstrual blood loss, pregnancy, and conditions that affect absorption such as coeliac disease.
Ferritin is the protein that stores iron in your cells. It reflects your total iron reserves. A low ferritin level is often the earliest sign of iron depletion, sometimes appearing before iron itself drops below range. Ferritin can be raised by inflammation, infection or liver conditions, so it is best read alongside a CRP marker if available.
Transferrin is the protein that transports iron through the bloodstream. Transferrin saturation is the percentage of transferrin that is currently carrying iron. Together, they help distinguish between iron deficiency, anaemia of chronic disease, and iron overload (haemochromatosis). These markers are influenced by the same factors as iron and ferritin, plus hydration and recent infection.
Key vitamins for blood health
Active B12 (holotranscobalamin) is the biologically active fraction of vitamin B12 available to your cells. B12 supports red blood cell formation, nerve health and energy production. Low B12 can cause fatigue, memory problems, tingling or numbness. B12 is mainly found in animal products; deficiency is more common in vegans, vegetarians, people over 60, and those taking metformin or proton pump inhibitors long-term.
Folate (serum folate) is vitamin B9, essential for DNA synthesis and red blood cell maturation alongside B12. Low folate contributes to fatigue and can cause a macrocytic anaemia (large red blood cells). Folate comes from green leafy vegetables, beans and fortified foods; deficiency can result from poor diet, pregnancy (requirements double), alcohol excess, or certain medications such as methotrexate.
UK reference ranges
Reference ranges vary by laboratory, age and sex. The values below are typical UK ranges reported by NHS sources and UKAS-accredited laboratories; your Lola results will show the specific reference range applied to your sample. Clinical thresholds are what doctors act on — any "optimal" framing below is a non-clinical wellness perspective.
| Marker | Typical UK reference range | Units | Plain-language meaning |
|---|---|---|---|
| Iron (Fe) | Men: 11.6–31.3 / Women: 9.0–30.4 | µmol/L | Reflects iron circulating in the blood; low suggests depletion, high may indicate overload |
| Ferritin | Men: 20–300 / Women: 15–200 | µg/L | Body's iron stores; low is the earliest sign of iron depletion, high can signal inflammation or iron overload |
| Transferrin | 2.0–4.0 | g/L | Iron transport protein; rises when iron is low, falls when iron is high |
| Transferrin saturation | 20–50 | % | Percentage of transferrin carrying iron; low supports iron deficiency, high may suggest haemochromatosis |
| Active B12 | >35 | pmol/L | Biologically available B12; below range suggests deficiency, borderline may need further investigation |
| Folate (serum) | >4.0 | µg/L | Body's folate status; low impairs red blood cell maturation and cell division |
Causes of low and high results
The causes below are things to discuss with your GP — a single out-of-range result is not a diagnosis.
Low results
| Marker | Common causes of low results to discuss with your GP |
|---|---|
| Iron | Insufficient dietary iron, heavy menstrual periods, pregnancy, coeliac disease or other malabsorption, chronic blood loss (e.g. gastrointestinal) |
| Ferritin | Iron depletion (often the first marker to fall), inadequate diet, heavy periods, pregnancy |
| Transferrin saturation | Iron deficiency, blood loss, poor absorption |
| Active B12 | Vegan or vegetarian diet, pernicious anaemia, long-term metformin or proton pump inhibitor use, bowel surgery affecting the terminal ileum |
| Folate | Poor dietary intake, pregnancy (increased demand), alcohol excess, medications such as methotrexate or anticonvulsants |
High results
| Marker | Common causes of high results to discuss with your GP |
|---|---|
| Iron | Iron supplementation, haemochromatosis, frequent blood transfusions, liver damage |
| Ferritin | Inflammation or infection, liver disease, haemochromatosis, metabolic syndrome |
| Transferrin saturation | Haemochromatosis, iron overload, excessive supplementation |
| Active B12 | Supplementation, liver disease, kidney disease (reduced clearance) |
| Folate | Supplementation, B12 deficiency (folate accumulates if B12 is low), small intestinal bacterial overgrowth |
Which at-home blood test to choose
A focused panel: Blood Health 6
The Blood Health 6 panel measures all six markers above — active B12, ferritin, folate, iron, transferrin and transferrin saturation — making it the most direct way to assess iron stores and the key vitamin deficiencies that affect blood health. For adults aged 18+. It is available by AutoDraw upper-arm device or fingerprick, or with a home phlebotomist visit or partner clinic venous draw — see the product page for current prices and collection options.
Biomarkers: 6
Turnaround: usually within 2 working days of lab receipt
Doctor review: included (GMC-registered doctor)
Who it suits: anyone who wants a focused check on iron and the B vitamins most relevant to energy and red blood cell health, without paying for a broader panel
Broader panels that include iron and vitamin markers
If you want to monitor iron and vitamins alongside hormones, thyroid function, cholesterol or other health areas, these panels include relevant markers. All are for adults aged 18+, include a GMC-registered doctor review, and offer home phlebotomist visit, partner clinic venous draw or own-phlebotomist collection — see each product page for current prices and options.
| Panel | Key iron/vitamin markers included | Biomarkers | Turnaround |
|---|---|---|---|
| Core Health 45 | Ferritin, active B12, vitamin D, magnesium | 45 | 2 working days |
| Vital Check 56 | Ferritin, active B12, folate, vitamin D, magnesium | 56 | 2 working days |
| Peak Insights 70 | Iron, transferrin, transferrin saturation, ferritin, active B12, vitamin D, magnesium | 70 | 4 working days |
| Female Active Boost 39 | Iron studies, active B12, vitamin D, magnesium | 39 | 2 working days |
| Male Active Boost 36 | Iron studies, active B12, vitamin D, magnesium | 36 | 2 working days |
Single-marker add-ons
If you are already ordering a main panel, you can add individual markers. Add-ons require a venous draw and are only sold alongside a main test:
Vitamin B6 (adds approximately 6 business days)
Vitamin B2 (adds approximately 6 business days)
Vitamin B1 (adds approximately 6 business days)
How at-home blood testing works
Choose your test on the Lola Health website. You can compare panels side by side at lolahealth.com/collections/all.
Select your collection method at checkout. Options depend on the panel: a phlebotomist home visit (mainland Great Britain, Monday to Friday), a venous draw at one of over 170 partner clinics, arranging your own phlebotomist, or — on smaller panels such as Blood Health 6 — the AutoDraw upper-arm device or fingerprick.
Prepare for your sample. Most tests need no fasting. If your panel includes cholesterol or triglycerides, fast for 8–12 hours beforehand (water is allowed). Pause high-dose biotin supplements for 48 hours. Avoid intense exercise for 24 hours. Do not stop prescribed medication; let Lola know which medications you take.
Have your sample taken. The phlebotomist posts it to the lab via Royal Mail Tracked 24, typically reaching the lab within 24–36 hours.
Receive your results. The UKAS-accredited (ISO 15189) UK partner laboratory processes the sample. Results are usually available within 2 working days of lab receipt (Peak Insights 70: 4 working days). A GMC-registered doctor reviews every blood panel and writes a personalised analysis highlighting markers outside the reference range. Results appear in the Lola app (iOS and Android) with trends over time and can be exported as PDF or CSV to share with your GP.
The phlebotomy appointment and doctor review are included in the panel price. The only additional fees are for a failed blood draw or a cancellation or rescheduling within 24 hours. Free UK delivery applies to all kits.
What to do with your results
Lola provides wellness insight and does not diagnose conditions. If any marker falls outside the reference range, the doctor's report will flag it and offer context, but you should always discuss your results and any symptoms with your GP, who can arrange further investigation, prescribe treatment, or refer you to a specialist if needed.
Common next steps to discuss with a GP:
Low ferritin or iron: dietary changes (iron-rich foods with vitamin C to aid absorption), iron supplements, or investigation of a source of blood loss.
Low B12: dietary review, B12 supplementation (tablets or injections, depending on the cause), or testing for intrinsic factor antibodies if pernicious anaemia is suspected.
Low folate: dietary changes and folic acid supplementation; important to address before and during pregnancy.
High ferritin or iron: your GP may investigate haemochromatosis, inflammation, or liver conditions.
Never start high-dose supplements based on a test result alone — excessive iron can be harmful, and B12 or folate supplementation can mask other deficiencies. Your GP is best placed to advise on dosing and duration.
Related markers to consider reading alongside
Iron and ferritin results are more meaningful when interpreted together. Consider:
Transferrin and transferrin saturation — included in Blood Health 6 and Peak Insights 70; help distinguish iron deficiency from other causes of anaemia.
CRP (C-reactive protein) — an inflammation marker that can raise ferritin independently of iron stores. Included in Core Health 45, Vital Check 56, and Peak Insights 70.
Full blood count (FBC) — haemoglobin, MCV and MCH help confirm whether low iron or B12 is causing anaemia. Included in Core Health 45, Vital Check 56, Female Active Boost 39 and Male Active Boost 36.
Vitamin D — low vitamin D often coexists with other nutrient deficiencies, especially in the UK during autumn and winter. Included in all the broader panels listed above.
FAQ
Can I test just my iron level without a full panel?
The Iron add-on measures iron alone, but add-ons require a venous draw and can only be purchased alongside a main panel. For a standalone iron assessment, the Blood Health 6 panel measures iron alongside ferritin, transferrin, transferrin saturation, active B12 and folate — giving a much more complete picture of your iron status.
How often should I monitor iron and vitamin levels?
There is no single recommended interval. If you are correcting a known deficiency, retesting after 3–6 months is common to check whether supplementation is working. For general wellness monitoring, many people test annually. The Lola app shows trends over time, which makes it easier to spot gradual changes. Discuss retesting frequency with your GP.
Do I need to fast before an iron or vitamin blood test?
No. Iron, ferritin, B12 and folate do not require fasting. If your panel also includes cholesterol or triglycerides, an 8–12 hour fast is needed (water is allowed).
Are fingerprick and venous results equally accurate?
Venous blood draws are considered the gold standard for most markers. Fingerprick and AutoDraw samples are adequate for the panels that offer them, but some markers — particularly those affected by small sample volumes or capillary contamination — are more reliably measured from a venous draw. Blood Health 6 is available by AutoDraw or fingerprick because its six markers perform well with those collection methods.
What if my ferritin is high but my iron is low?
This pattern can suggest inflammation or infection raising ferritin independently of iron stores (anaemia of chronic disease), rather than straightforward iron deficiency. Reading ferritin alongside CRP and transferrin saturation helps clarify the picture. Discuss this pattern with your GP, who may want to investigate further.
This article provides wellness information and does not diagnose or treat any condition. Always discuss your blood test results and any symptoms with your GP. Medical disclaimer.
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