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Folate (Reduced) in Serum

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

This test measures the amount of active folate (vitamin B9) in your blood, which is important for red blood cell production and DNA synthesis.

Quick summary

["Low folate levels may indicate poor nutrition or certain medical conditions."]

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

Key facts at a glance

LOINC
35953-9
Short code
MR Face
Synonyms
MR Face
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
mr
CPT
86430
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 healthcare provider may order this test to check for folate deficiency, especially if you have symptoms like fatigue, weakness, or unusual bleeding. It’s also used during pregnancy to prevent neural tube defects in the baby. Sometimes, it’s part of a broader evaluation for anemia or other blood disorders.

What to Expect Before the Test

No special preparation is needed, but you may be asked to fast for 8–12 hours before the test if it’s part of a metabolic panel. Bring any medications you’re currently taking, as some (like certain blood pressure drugs) can affect results.

How the Test Works

A blood sample is drawn from a vein in your arm. The sample is sent to a lab where it’s analyzed using an immunoassay method to measure the reduced folate concentration.

What the Results Mean

Results are compared to a reference range, but exact values can vary by lab. Low levels may suggest dietary deficiencies, malabsorption issues, or conditions like alcoholism. High levels might indicate folate supplements or certain genetic disorders.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Serum Folate (Reduced)

Frequently asked questions

What causes low folate levels?
Low folate levels can result from poor diet (low intake of leafy greens, fortified foods), alcohol use, certain medications (like anticonvulsants or chemotherapy drugs), or conditions like celiac disease or Crohn’s disease that affect nutrient 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. Your healthcare provider will discuss them with you during your follow-up visit.
Can folate levels be affected by supplements?
Yes, folate supplements (especially high-dose prenatal or folic acid) can raise your levels. If you take supplements, let your provider know to avoid misleading results.
  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