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Folate The B vitamin for making new cells

Also called Folic acid, Vitamin B9 and Serum folate Not on a standard checkup No fasting needed

The short answer

Folate is the B vitamin your body uses to make new cells, including red blood cells. Since the US started adding folic acid to flour, low levels have become rare: under 1% of women of childbearing age.3

A good result
4 ng/mL or higher.1 Labcorp only flags results of 3.0 or under, so a result of 3.1 to 3.9 won’t show as low on your report.4
If yours is low
It usually comes from a poor diet, heavy drinking, a gut condition or a medicine. Check B12 before treating, because folic acid can hide a B12 shortage.5,7
Should you test?
Most people don’t need to.6 Whatever your result, if you could get pregnant, take 0.4 to 0.8 mg of folic acid a day.2

Check your result

Type the number from your report. It stays on this page.

3.1 4 20.1
  • Low Under 3.1
  • Borderline 3.1 to 3.9
  • Normal 4.0 to 20.0
  • High 20.1 or more

Enter your result to see what it means and what to do next.

Got a result from another lab? Ask Picardo about it. The app explains your results, and a physician can follow up.

Cutoffs from the WHO.1 Labcorp flags results of 3.0 or under.4 The bar isn’t to scale.

What is a normal folate level?

This test measures serum folate, which shows how much folate you’ve had recently.1 Labcorp flags results of 3.0 ng/mL or under.4 The WHO uses two cutoffs: under 3, where anemia becomes more likely, and under 4, where your cells start to run short:1

Low 3.0 ng/mL or under

Low: find out why

At this level, folate is low enough for anemia to become more likely, and Labcorp flags it.1,4 With fortified flour, that usually means something else is going on, such as heavy drinking, a gut condition or a medicine.3,7

How worried to be

Treatable. See a clinician in the next few weeks.

What to do next
  1. 1 Check B12 at the same time. Folic acid can fix the anemia of low B12 while nerve damage carries on.5,7
  2. 2 Ask about folic acid tablets, and about the cause.7
  3. 3 One low result can reflect a few days of eating badly. Low results again over a month mean a real shortage.1
Borderline 3.1 to 3.9 ng/mL

Normal on your report, but borderline

Labcorp won’t flag this.4 But the WHO counts serum folate under 4 as deficient, because below it your cells start to run short of folate.1

How worried to be

Not urgent.

What to do next
  1. 1 Eat more folate. Leafy greens, fruit, beans and fortified bread and cereals are good sources.2,7
  2. 2 Recheck in a month or so. A single result mostly reflects what you’ve eaten lately.1
  3. 3 If you drink heavily or have a gut condition, ask a clinician about a supplement.7
Normal 4.0 to 20.0 ng/mL

Normal

Your folate is fine.1 That’s true of nearly everyone in the US since folic acid was added to flour.3

How worried to be

Nothing to worry about.

What to do next
  1. 1 If you could become pregnant, still take 0.4 to 0.8 mg of folic acid a day. A normal result doesn’t replace it.2
High Over 20.0 ng/mL

Higher than usual

This is above the usual range, though the WHO’s cutoff of 20 reflects old test limits rather than any known harm.1 It usually reflects folic acid from supplements and fortified foods. High folate hasn’t been shown to cause harm, though researchers are still studying it.8 A damaged sample can also make the result read falsely high, and biotin supplements can upset it.4

How worried to be

Nothing to worry about on its own.

What to do next
  1. 1 Keep folic acid from supplements and fortified foods to 1,000 µg (1 mg) a day or less, unless a clinician advises more.5
  2. 2 If you take high-dose folic acid, make sure your B12 is normal. Folic acid can hide a B12 shortage.5
Folate test, $5.00
Results in 2 to 3 days, explained in the app
Order

What is folate?

Think of folate as ink for copying your DNA. Every new cell needs a fresh copy, so the cells your body makes fastest, like red blood cells, show a shortage first.

Folate is vitamin B9. Your body uses it, together with B12, to make DNA, which every new cell needs, including red blood cells.4 Natural folate is in leafy greens, fruit, beans and liver. Folic acid is the man-made form in supplements and fortified foods.2,7

Why is low folate rare in the US?

Since 1998, the US has required folic acid in enriched grain products, such as flour, bread, pasta and rice, at 140 µg per 100 g. Afterwards, low serum folate in women of childbearing age fell from about 30% to under 1%, and neural tube defects such as spina bifida fell by about 28%.3

What causes low folate?

  • Eating few vegetables, fruit or fortified grains7
  • Heavy drinking7
  • Celiac disease and other conditions that block absorption7
  • Pregnancy and breastfeeding, which raise how much you need7
  • Medicines that block folate, including methotrexate, trimethoprim, triamterene, metformin and some seizure medicines such as phenytoin7
  • Kidney dialysis7

Low folate and low B12 cause the same kind of anemia, with large red blood cells, so they’re usually checked together.7

How to raise folate

  • Folic acid tablets

    Fix a shortage reliably. Check B12 first, because folic acid can hide a B12 shortage.5,7

    How much it helps
    A lot
    How sure we are
    Very sure
  • Folate-rich and fortified foods

    Leafy greens, fruit, beans and fortified bread and cereals. Your body absorbs the folic acid in fortified foods best.2,7

    How much it helps
    Some
    How sure we are
    Fairly sure
  • Drinking less alcohol

    Alcohol gets in the way of absorbing and using folate.7

    How much it helps
    Some
    How sure we are
    Fairly sure

Don’t take folic acid for a suspected shortage before your B12 is checked. It can correct the anemia of a B12 shortage while nerve damage carries on.5

Should you take folic acid if you could get pregnant?

Yes. US guidelines recommend a daily supplement with 0.4 to 0.8 mg of folic acid for anyone planning to or able to get pregnant. It lowers the risk of neural tube defects such as spina bifida, and the evidence is strong: it’s a grade A recommendation.2

The neural tube forms in the first month of pregnancy, and nearly half of US pregnancies are unplanned. So start at least a month before you might conceive, and keep going through the first 2 to 3 months of pregnancy. Fortified food alone doesn’t give enough for the full benefit.2

A normal folate result doesn’t change any of this. If you’ve had a pregnancy affected by a neural tube defect, have a family history of one or take a medicine that blocks folate, this advice doesn’t cover you, so ask a clinician about yours.2

Who should get a folate test?

Most people don’t need one. Canada, which fortifies flour too, advises testing folate only when a blood count shows anemia with large red blood cells and there’s a reason to suspect a shortage, such as:6

  • Heavy drinking
  • Celiac disease or another condition that affects absorption
  • A very restricted diet, without a multivitamin

If you test folate, test B12 too.7 If you take methotrexate or leucovorin, the folate test isn’t reliable.4

How to get a folate test, and what it costs

A folate test costs $5.00 through Picardo.

Order the test

Folate test

$5.00
Labcorp 002014 · no fasting needed
Order folate
  • Results in 2 to 3 days, in the app
  • Physician follow-up if you want one
  • Free Labcorp draw, or $75 at home
  • No other fees. HSA and FSA eligible.

It’s also part of the Base Core Annual – Men, Base Core Annual – Women, Heart Health, Brain Health Screening, Postpartum and Celiac / GI panels, if you’d rather test more at once.

Already have a result? Ask Picardo about it

Questions people ask

Do I need a folate test before getting pregnant?

No. Take 0.4 to 0.8 mg of folic acid every day, starting at least a month before you conceive and through the first 2 to 3 months of pregnancy, whatever your level.2,6 Red blood cell folate targets for pregnancy apply to whole populations, not to one person’s result.1

What’s the difference between serum and red blood cell folate?

Serum folate, this test, reflects what you’ve eaten recently. Red blood cell folate reflects the last few months, because red cells keep the folate they took in when they were made and live about 120 days.1

Is folate the same as folic acid?

Folate is the natural form, in foods such as leafy greens and beans. Folic acid is the man-made form in supplements and fortified foods, and your body absorbs it better.2,5,7

Can you take too much folic acid?

The US upper limit for adults is 1,000 µg a day from supplements and fortified foods, not counting natural folate. The concern is that high doses can hide a B12 shortage and let nerve damage progress.5

Can supplements affect the result?

Yes. Stop biotin, common in hair and nail supplements, for at least 3 days before the test, because it can upset it.4 Folic acid you took recently raises serum folate, which mostly reflects what you’ve had lately.1

What is leucovorin, and does it treat autism?

Leucovorin, or folinic acid, is a prescription form of folate. In March 2026 the FDA added a new use for it, cerebral folate transport deficiency caused by a variant in the FOLR1 gene, a rare inherited condition. Autism isn’t among its approved uses.9 It also makes the folate blood test unreliable.4

Often checked alongside

Vitamin B12
Needed for nerves and red blood cells
Homocysteine
An amino acid that rises when B12 or folate is low
MCV
Average red blood cell size
Hemoglobin
Carries oxygen; low levels mean anemia

Test details

Labcorp test
Folate (Folic Acid), 002014
LOINC
2284-8
Sample
Blood (serum)
Fasting
Not needed
Typical lab range
Over 3.0 ng/mL4
Units
ng/mL, the same as µg/L. For nmol/L, multiply by 2.266.

Sources

  1. 1 World Health Organization. Serum and red blood cell folate concentrations for assessing folate status in populations. Vitamin and Mineral Nutrition Information System. Geneva: WHO; 2015. WHO/NMH/NHD/EPG/15.01. www.who.int/publications/i/item/WHO-NMH-NHD-EPG-15.01
  2. 2 US Preventive Services Task Force; Barry MJ, Nicholson WK, Silverstein M, et al. Folic acid supplementation to prevent neural tube defects: US Preventive Services Task Force reaffirmation recommendation statement. JAMA. 2023;330(5):454–459. doi.org/10.1001/jama.2023.12876
  3. 3 Williams J, Mai CT, Mulinare J, et al. Updated estimates of neural tube defects prevented by mandatory folic acid fortification — United States, 1995–2011. MMWR Morb Mortal Wkly Rep. 2015;64(1):1–5. pubmed.ncbi.nlm.nih.gov/25590678/
  4. 4 Labcorp. Folate (folic acid), test 002014. Labcorp test menu. Accessed October 28, 2026. www.labcorp.com/tests/002014/folate-folic-acid
  5. 5 Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Chapter 8: Folate. Washington, DC: National Academy Press; 1998. doi.org/10.17226/6015
  6. 6 Choosing Wisely Canada. Medical biochemistry: recommendation 1, serum folate testing. Canadian Association of Medical Biochemists. Updated September 2026. choosingwiselycanada.org/recommendation/medical-biochemistry/
  7. 7 Johnson LE. Folate deficiency. Merck Manual Professional Edition. Updated June 2026. www.merckmanuals.com/professional/nutritional-disorders/vitamin-deficiency-dependency-and-toxicity/folate-deficiency
  8. 8 Maruvada P, Stover PJ, Mason JB, et al. Knowledge gaps in understanding the metabolic and clinical effects of excess folates/folic acid: a summary, and perspectives, from an NIH workshop. Am J Clin Nutr. 2020;112(5):1390–1403. doi.org/10.1093/ajcn/nqaa259
  9. 9 GlaxoSmithKline. WELLCOVORIN (leucovorin calcium) tablets: prescribing information. Revised March 2026. www.accessdata.fda.gov/drugsatfda_docs/label/2026/018342s015lbl.pdf

Updated 28 Oct 2026.

This is general health information, not medical advice: talk to your clinician about your results and before changing any treatment.