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Folate (Substance Concentration) in Serum or Plasma

Published: August 9, 2026Updated: August 16, 2026

This test measures the amount of folate, a B vitamin important for red blood cell production and DNA synthesis.

Quick summary

["Helps assess vitamin B12 and folate status, which are critical for preventing birth defects and anemia."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
49534-1
Short code
FLUBV Ag Islt Ql IF
Synonyms
FLUBV Ag Islt Ql IF
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
if
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Your doctor may order this test to check for deficiencies in folate, which can cause fatigue, weakness, or neurological issues. It’s often done alongside tests for vitamin B12 or hemoglobin to diagnose conditions like megaloblastic anemia or pernicious anemia.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before drawing blood. Wear a loose shirt for easy access to your arm.

How the Test Works

A healthcare provider will insert a needle into your arm to draw blood into a test tube. The sample is then sent to a lab for analysis using an immunoassay method to measure folate levels.

What the Results Mean

Low levels may indicate poor nutrition, malabsorption issues, or certain medications (like anticonvulsants) affecting folate absorption. High levels could suggest folate supplements or liver disease.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: Folate deficiency is common in pregnant women, alcoholics, or those with conditions like celiac disease or Crohn’s disease. It’s also linked to increased risk of certain cancers and heart disease. Regular monitoring is important for patients on long-term folate supplements.

Short name

Serum Folate

Frequently asked questions

What causes low folate levels?
Low folate can result from poor diet (low intake of leafy greens, beans, or fortified foods), alcohol use, certain medications (e.g., antacids, birth control pills), or gastrointestinal disorders that impair absorption.
How long does it take to get results?
Results are typically available within 1–3 business days, depending on your lab’s processing time. Follow-up with your doctor if you have concerns about your results.
Can folate levels change with diet?
Yes, dietary changes can significantly impact folate levels. Increasing intake of folate-rich foods (like spinach, lentils, or fortified cereals) may raise levels, while avoiding alcohol or certain medications can help maintain balance.
  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 16, 2026. · Read our editorial policy