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Folate and Vitamin B12 Serum Levels (Qualitative/Quantitative Screening)

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

This test measures your blood levels of folate (vitamin B9) and vitamin B12 (cobalamin), two essential B vitamins that play key roles in red blood cell production, nerve function, and DNA synthesis.

Quick summary

["Checks if your vitamin levels are sufficient or deficient, which can affect energy, blood health, and nerve function."]

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

Key facts at a glance

LOINC
93718-5
Short code
F tular IgG+IgM Ser-Imp
Synonyms
F tular IgG+IgM Ser-Imp
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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 This Test Matters for You

Vitamin B12 and folate are critical for preventing serious conditions like anemia, nerve damage, or birth defects. Low levels may indicate poor diet, absorption issues, or underlying health problems like pernicious anemia or celiac disease.

How the Test Works

Blood is drawn from a vein, typically in your arm. The sample is tested using a sensitive immunoassay (IA) method to detect and quantify folate and B12 concentrations in your serum.

What to Expect Before the Test

No special preparation is needed, but you may want to eat a normal meal the day of the test. If you’re taking folate or B12 supplements, let your healthcare provider know, as this may affect results.

Possible Results & Next Steps

Results may be reported as separate values for folate and B12. Low levels could prompt further testing (e.g., methylmalonic acid or homocysteine) or dietary counseling. High levels may require monitoring if you’re taking supplements.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low folate or B12 levels can cause anemia (fatigue, weakness), neurological issues (tingling, memory problems), or increased risk of pregnancy complications. High levels may indicate over-supplementation or liver disease. Your doctor will interpret results in the context of your symptoms and medical history.

Short name

Folate & B12 Screening (Serum)

Frequently asked questions

What causes low vitamin B12 or folate levels?
Common causes include poor diet (low intake of leafy greens, meat, or fortified foods), malabsorption (e.g., from celiac disease, atrophic gastritis), or certain medications (e.g., metformin). Chronic conditions like Crohn’s disease or alcoholism may also contribute.
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 healthcare provider if you have questions about your specific results.
Can I take supplements before the test?
Yes, but inform your doctor or lab technician if you’re taking folate or B12 supplements. They may recommend timing (e.g., stopping 48 hours before) or adjusting interpretation of your 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