Serum/plasma concentration of folate (vitamin B9)
This test measures the amount of folate, a B vitamin important for red blood cell production and DNA synthesis, in your blood.
["Folate helps prevent birth defects and supports overall red blood cell health."]
Key facts at a glance
- LOINC
- 98904-6
- Short code
- OF Pnl RBC
- Synonyms
- OF Pnl RBC
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 85041
- SNOMED
- 900000000000003001
- 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 a folate test to check for deficiencies, especially if you have symptoms like fatigue, weakness, or unusual bleeding. It’s also used in pregnancy to prevent neural tube defects in the baby. Folate levels can also be monitored in people with certain medical conditions, such as alcoholism or malabsorption disorders.
What to Expect Before the Test
No special preparation is usually needed, but your doctor might advise stopping certain medications that affect folate levels (like some anticonvulsants) for a few days before testing. If you’re pregnant, let your doctor know—some tests may be adjusted for safety.
What Happens During the Test?
A blood sample is drawn from a vein, typically in your arm. The sample is sent to a lab to measure folate concentration using a specialized immunoassay method.
What Do the Results Mean?
Results are compared to a reference range, but exact values can vary by lab. Low levels may indicate poor nutrition, certain medical conditions, or increased needs (like pregnancy). High levels might suggest folate supplements or certain medications.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: Folate plays a critical role in cell growth and red blood cell production. Deficiencies can lead to anemia, neurological issues, or complications in pregnancy. Monitoring folate helps manage conditions like megaloblastic anemia or prevent birth defects in high-risk pregnancies.
Short name
Folate Level
Frequently asked questions
Why might my folate levels be low?
What are common symptoms of folate deficiency?
Do folate supplements always correct low levels?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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