Quick Facts
- Sample: 1 mL serum (minimum 0.5 mL); collected in a serum gel or red-top tube
- Fasting: 8 hours required for best accuracy
- Turnaround: 1–3 business days. May take longer due to weather, holidays, or lab delays.
Benefits
- Know your folate status quickly—results in as little as 1–3 business days.
- Catch deficiency early before symptoms like fatigue or anemia develop.
- Support pregnancy planning with data-backed folic acid intake guidance.
- Order without a doctor's referral—private, direct-to-consumer access.
- Pair seamlessly with B12 and homocysteine for a complete picture.
- Act on results fast: simple dietary changes or supplements can correct a deficiency.
Who Is This Test For?
- Pregnant women or those planning pregnancy — CDC recommends 400 mcg folic acid daily to reduce neural tube defect risk (CDC 2025).
- People with fatigue or unexplained anemia — folate deficiency is a common cause of macrocytic anemia.
- Those with poor diet or malabsorption conditions — celiac disease, Crohn's, or alcohol use can deplete folate.
- Patients on certain medications — methotrexate and other folate antagonists can reduce folate levels.
- Health-conscious adults monitoring nutrient status — useful baseline for anyone optimizing wellness.
- Anyone with a family history of folate-related conditions — proactive screening supports early intervention.
How It Works – Just 3 Steps
- Order online — complete your purchase without needing a doctor's order, and schedule an appointment at a nearby lab location.
- Get your blood drawn — visit the lab fasted (8 hours); a quick blood draw is all that's needed.
- Review your results — receive secure results online within 1–3 days and share with your provider if needed.
FAQ
What does this test measure? It measures serum folate (vitamin B9) levels in your blood to assess whether you have adequate folate for healthy cell function and development. (Mayo Clinic Laboratories 2026)
Do I need to fast before the test? Yes—8 hours of fasting is required for the most accurate results. Avoid biotin supplements for at least 8 hours before your draw; if you take high-dose biotin, wait 72 hours.
What does a low result mean? A serum folate result below 4 mcg/L suggests deficiency. However, results should be interpreted alongside B12, homocysteine, and your symptoms, as causes can overlap. (Mayo Clinic Laboratories 2026)
Can recent supplements affect my results? Yes. Taking folic acid supplements shortly before the test can temporarily raise serum folate, masking a true deficiency. Inform your provider of any recent supplementation. (Mayo Clinic Laboratories 2026)
Is this test only for women? No. While pregnancy planning is a key use case, anyone with suspected deficiency, anemia, or poor nutrient absorption can benefit from testing. (Mayo Clinic Laboratories 2026)
How is this different from an RBC folate test? Serum folate reflects recent intake; RBC folate reflects longer-term stores. Mayo Clinic prefers serum folate because RBC assays have greater analytic variability.
More Details
What is the purpose of this test?
A serum folate test checks your blood level of vitamin B9 to identify folate deficiency and its related complications, including macrocytic anemia. Folate is essential for DNA synthesis, cell growth, and fetal development. The test is especially valuable when you want direct, fast access to nutrient data without scheduling a specialist visit. (Mayo Clinic Laboratories 2026; CDC 2025)
Who would benefit from this test?
Anyone suspecting low folate intake, experiencing unexplained fatigue, or dealing with anemia symptoms can benefit. Mayo Clinic highlights suspected deficiency and macrocytic anemia workups as primary indications. CDC emphasizes women capable of becoming pregnant as a critical prevention group, given folate's role in preventing neural tube defects. People with malabsorption disorders, alcohol dependence, or on folate-antagonist medications are also strong candidates. (CDC 2025; Mayo Clinic Laboratories 2026)
When should I order this test?
Order this test when you have symptoms of deficiency (fatigue, weakness, mouth sores), when evaluating macrocytic anemia, or before and during pregnancy. It's also appropriate when you've recently changed your diet, started a new medication, or want a baseline nutrient screen. Remember to fast 8 hours and avoid recent folic acid use for the most accurate result. (Mayo Clinic Laboratories 2026)
How do I interpret the results?
> 5.4 ng/mL
- Meaning: Normal folate status
- Typical Action: Maintain diet; retest as needed
4.0–5.4 ng/mL
- Meaning: Borderline / low-normal
- Typical Action: Review diet; consider B12 and homocysteine follow-up
< 4.0 ng/mL (or < 4.0 mcg/L)
- Meaning: Suggestive of deficiency
- Typical Action: Consult provider; evaluate B12, homocysteine, and MMA
Fast fact: Serum folate is relatively nonspecific—a normal result doesn't always rule out all folate-related problems if recent supplementation has temporarily elevated levels. Always interpret in clinical context. (Mayo Clinic Laboratories 2026)
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
- Fast for 8 hours before your blood draw for optimal accuracy.
- Hold biotin supplements for at least 8 hours prior; if on mega-doses, wait 72 hours, as biotin can interfere with immunoassay results.
- Note recent folic acid use — tell your provider if you've taken supplements recently, as this can affect interpretation.
- Avoid methotrexate or folate antagonists before testing when possible; discuss timing with your prescriber. (Mayo Clinic Laboratories 2026)
How often should I get tested?
- Pregnancy planning or early pregnancy: Once at baseline; repeat as directed by provider
- Monitoring supplementation or dietary changes: Every 3–6 months until stable
- Malabsorption condition or chronic medication use: Every 6–12 months, or per provider guidance
- General wellness screening (low-risk adults): Annually or as needed
Why early detection matters
Before mandatory folic acid fortification in 1998, folate deficiency affected roughly 12% of women of childbearing age. Today, thanks to fortification, deficiency in the U.S. general population is below 1%. (CDC Second Nutrition Report 2024) Still, fortification alone isn't enough for everyone—CDC estimates that combining supplements with fortified foods could prevent up to 700 additional neural tube defects per year. (CDC 2025) Testing lets you confirm your status rather than assume it.
Related tests you may consider
Vitamin B12 Blood Test — pairs with folate because both deficiencies cause macrocytic anemia and must be distinguished for correct treatment. (Mayo Clinic Laboratories 2026)
Homocysteine — rises when folate (or B12) is low; useful as a functional marker to clarify borderline folate results. (Mayo Clinic Laboratories 2026)
Methylmalonic Acid (MMA) — helps separate folate deficiency from B12 deficiency; MMA is typically normal in folate deficiency but elevated in B12 deficiency. (Mayo Clinic Laboratories 2026)
