Clinic appointment
Serum Folate Test
Folate measured in serum, which reflects your recent intake of the B vitamin found in green vegetables, pulses and fortified breads and cereals.
- Doctor-reviewed results
- Laboratory analysis
- 1 to 2 working days from lab receipt
- No fasting required
What’s included
1 marker measured
Folate (serum)
Measures folate in the blood serum to check for folate deficiency, a cause of anaemia. A low result suggests deficiency but does not confirm it, as there is a borderline zone. If deficiency is still suspected despite a normal result, red cell folate may be measured once B12 deficiency has been ruled out.
Overview
Folate is needed to make red blood cells and matters a great deal around pregnancy, and low levels turn up with a limited diet, heavy drinking, coeliac disease and some medicines. Serum folate reflects what you have eaten over recent days, and it is the first test UK haematology guidance uses to check folate.
Folate matters for making red blood cells and for the healthy development of a pregnancy, and low levels turn up with a limited diet, heavy drinking, coeliac disease and some medicines. Serum folate reflects your recent intake, so folate-rich food or a folic acid supplement in the days before your test can raise a low result. Red cell folate is included in the Anaemia Check, the Vitamin B Check and the Advanced Vitamin Check.
Who this is for and who it isn’t
Who it’s for
- Adults aged 18 and over
- Anyone whose clinician has asked for a folate level
- People with a limited diet, coeliac disease or absorption problems
Who it isn’t for
- Serum folate reflects your recent intake, so folate-rich food or a folic acid supplement in the days before your test can raise a low result. Red cell folate is included in the Anaemia Check, the Vitamin B Check and the Advanced Vitamin Check. Folate is also almost always read with B12, because treating low folate while B12 is low can make nerve symptoms worse, which is why a doctor looks at the pair.
- If you are trying for a baby, NHS advice is to take a 400 microgram folic acid supplement every day until you are 12 weeks pregnant, whatever this test shows. Some people are advised a higher dose, so check with your GP, midwife or pharmacist.
- Anyone with a new, severe or worsening symptom: contact your GP or call NHS 111. A test you buy today is not a substitute for being examined.
Common reasons people choose this test
- A limited or repetitive diet, or a clinician suspects low folate
- Wanting folate checked alongside B12
- Mouth ulcers or a sore tongue
- Coeliac disease or another condition affecting absorption
- Taking methotrexate or an anticonvulsant that affects folate
These are reasons people choose to test, not signs that something is wrong. A result is one part of a picture your doctor puts together with your history and an examination.
What your result looks like
Every result is shown with the unit and the reference range exactly as the laboratory reported it, with the doctor’s note underneath.
- Folate (serum)▼ Low
- Result
- 2.8 µg/L
- Range
- >3.9
| Marker | Result | Units | Range | Flag |
|---|---|---|---|---|
| Folate (serum) | 2.8 | µg/L | >3.9 | ▼ Low |
Doctor’s note (example)
Serum folate is below the range. It reflects the past few days, so diet and any recent supplement matter; a clinician would usually look at vitamin B12 alongside it, because the order in which the two are corrected is important.
Values above are examples. Your report shows your own results with the laboratory’s units and reference range for your age and sex, reviewed, signed and released by a GMC-registered doctor.
How it works
- You book your appointmentA trained clinician takes your sample at one of our London clinics. Nothing to do at home.
- The clinician takes your sampleA single clinic blood draw by a trained clinician
- The laboratory analyses itYour sample is processed for the measurements included in this test. Lab processing typically takes 1 to 2 working days from receipt of your sample.
- A doctor reviews and releases itA GMC-registered doctor reads every result and signs the report before it reaches you.
- Sample
- Clinic blood draw
- Preparation
- No fasting required
- Who it's for
- Any sex · ages 18+
How to prepare
What we can and can’t tell you
The reference range beside each result is the laboratory’s own. A result in range is not a clean bill of health and a result outside it is not a diagnosis. Most ranges cover about 95% of healthy people, so about 1 in 20 healthy people fall just outside any one range. No test result replaces an examination or your own doctor’s judgement, and none of these panels is a cancer screening programme.
Read the full note
The reference range printed beside each of your results is the laboratory's own, and it is the range that applies to your result. We do not apply a second range of our own, and we do not tell you that a result the laboratory reported as normal is nonetheless too low or too high. If you see a claim elsewhere that your result ought to sit inside a narrower band than the one the laboratory printed, treat it with caution and ask your doctor.
Some assays cannot give an exact figure above or below a certain point, and those results are reported the way the laboratory sends them, for example as a value greater than a stated number. A result in range is not a clean bill of health, and a result outside a range is not a diagnosis: most reference ranges are set to cover about 95% of healthy people, so some healthy people fall just outside them. No blood test replaces an examination, a scan or your own doctor's judgement, and none of these panels is a screening programme for cancer.
If you have a symptom that is new, severe, or getting worse, contact your GP or NHS 111 rather than waiting for a test result. In an emergency call 999.
Frequently asked questions
Do I need to fast?
No. Serum folate reflects what you have eaten recently, so tell the reviewing doctor if you have started a folic acid supplement or changed your diet.
Should I have B12 as well?
Ideally yes. The two are interpreted together, and the order in which they are corrected matters. Active B12 is available as a single test, and the Anaemia Check, Vitamin B Check and Advanced Vitamin Check include both B12 and folate.
Do supplements affect it?
Yes. Folic acid tablets and fortified foods both raise serum folate, so a result while supplementing shows the supplement rather than your baseline.
Why is this clinic only?
Serum folate is not one of the tests the laboratory accepts from a home finger-prick kit, so a nurse takes the sample at a clinic appointment.
How long do results take?
The laboratory typically takes 1 to 2 working days from receiving your sample. This does not include kit delivery, sample collection or return postage. A doctor reviews your results before they are released.
Can I choose a home kit or a clinic?
This test is a clinic blood draw, as it needs a venous sample for accuracy. We arrange a convenient appointment for you.
Is a doctor involved?
Yes. Every result is reviewed by a GMC-registered doctor who signs it off and explains what it means and what to do next.
Is it confidential?
Your results are available through your secure patient portal. Our privacy policy explains how your information is handled and when it may be shared to provide your care.
What happens to my sample and results?
Your sample is analysed at a UKAS-accredited laboratory (ISO 15189). A GMC-registered doctor then reads every result and signs the report before it is released, so nothing reaches you unreviewed. There is no option to receive results without a doctor reading them first. The report arrives in your secure portal in plain English: each result with its unit and the laboratory's own reference range, and the doctor's note on what the set means read together. If a result sits outside its range the report says so and explains what usually happens next, which is most often a conversation with your own GP, who can act on it alongside your history and examination. Most reference ranges are set to cover about 95% of healthy people, so about 1 in 20 healthy people fall just outside any one of them. On a report with many results it is common for one to sit just outside its range, and a single number on its own rarely tells the whole story. If a result needs urgent attention, the reviewing doctor is alerted straight away and we contact you by phone the same working day rather than leaving it in the portal for you to find. If a specific result needs rechecking, the reviewing doctor says so in your report.
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