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Folate in Blood (Serum or Plasma)

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of folate, a B vitamin essential for healthy cell function, particularly in red blood cells. Folate helps your body produce and maintain new cells and prevent certain types of anemia.

Quick summary

["Low folate may indicate nutritional deficiencies or hidden blood loss; high levels could signal vitamin excess or certain medical conditions."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
27088-4
Short code
Folate Bld Ql
Synonyms
Folate Bld Ql
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Ref low
2.7
Ref high
17
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why Folate Matters in Your Body

Folate is crucial for DNA synthesis and repair, red blood cell production, and preventing neural tube defects in pregnancy. Your body stores some folate, but it’s easily depleted by poor diet, alcohol use, or certain medications.

Common Causes of Low Folate

Folate deficiency often stems from poor dietary intake (e.g., limited leafy greens, fortified foods), malabsorption (e.g., celiac disease, Crohn’s), or medications like anticonvulsants or birth control pills. It can also result from chronic alcohol use or pregnancy.

When Folate Levels Are Monitored

Doctors check folate levels when diagnosing anemia (especially megaloblastic), evaluating nutritional status, or assessing patients with conditions like alcoholism, kidney disease, or certain cancers. Pregnant women may get tested to prevent birth defects.

What to Expect During the Test

A simple blood draw (usually from your arm) is needed. The sample is sent to a lab for analysis, often via immunoassay or other methods to detect folate concentration. Results are typically ready within 1–3 days.

Reference range

NCBI: Folate 2.7-17.0 ng/mLN/A

Specimen: whole-blood

Fasting for 8-12 hours preferred for some tests. Inform about supplements you are taking.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Folate Deficiency vs. Excess

Short name

Folate Level

Frequently asked questions

What does a low folate level mean?
A low folate level may signal a deficiency, which can cause fatigue, weakness, or anemia. It’s especially important to address if you have symptoms like pale skin, tongue inflammation, or unexplained bruising. Your doctor may recommend dietary changes, supplements, or further testing to identify the cause.
What does a high folate level mean?
High folate levels can occur due to excessive intake (e.g., supplements or fortified foods) or certain medical conditions like liver disease or hemolytic anemia. While rare, elevated levels may require monitoring, especially if you’re taking folate supplements long-term.
How often should I get this test?
Your doctor may recommend folate testing if you have risk factors (e.g., poor diet, pregnancy, or chronic illness). For general health, occasional screening isn’t typically advised unless symptoms or other tests suggest a need. Follow-up may include retesting if your levels are abnormal.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy