Can this result diagnose a condition on its own?

No. Laboratory results are interpreted with symptoms, medical history, specimen conditions and related tests.

Which reference range should I use?

Start with the performing laboratory's own reference interval; clinical cutoffs, when relevant, are separate sourced thresholds used for a specific purpose.

When should I discuss the result with a healthcare professional?

Results that are clearly outside range, persistent, symptomatic or unexpected should be reviewed by a healthcare professional.

Information about a laboratory test

Folate: What Does This Test Measure?

The Folate test measures DNA synthesis, cell division and red-blood-cell formation.

Test summary

Test name: Folate
Abbreviations: Folate, B9, Folic acid
Category: Vitamins / B-Complex
Panel: Nutritional / Anemia Evaluation
Specimen: Serum / plasma
Common units: ng/mL, nmol/L

What does the test measure?

The Folate test measures DNA synthesis, cell division and red-blood-cell formation.

Why is the test ordered?

Ordered when inadequate intake or absorption is suspected, in risk groups, or to assess supplement use; it is interpreted with related laboratory tests.

Information about a low result

Low serum folate can indicate inadequate folate status; serum levels are sensitive to recent intake. Vitamin B12 and homocysteine can add context.

Information about a high result

High folate can reflect supplements or fortified foods. Vitamin B12 status should also be considered so B12 deficiency is not overlooked.

Reference and clinical context

Start with the performing laboratory's reference interval, unit, specimen type and method. Numeric information on this page is stored as sourced example intervals or clinical thresholds.

Reference context 1

> 3 ng/mL

Population: General folate-status assessment
Specimen: Serum

Sourced serum folate adequacy threshold

This is a sourced clinical-context threshold and should not be used alone as a diagnosis or treatment decision. The laboratory report and clinical context take priority.

Reference ranges may vary by laboratory, method used, age, sex, pregnancy status, and clinical context. The reference range on your own laboratory report takes precedence.

Interpretation notes

Serum folate reflects recent intake, while erythrocyte folate can reflect longer-term status. Homocysteine is not specific for folate.

Related specialties

Internal Medicine
Hematology
Gastroenterology
Family Medicine

Frequently asked questions

More information about this test

Sources

Vitamin B12 – Health Professional Fact Sheet — NIH Office of Dietary Supplements
U.S. government nutrition reference · 2025 · Vitamin B12 status, serum B12, MMA and homocysteine interpretation · Verified: Aug 12, 2026
Folate – Health Professional Fact Sheet — NIH Office of Dietary Supplements
U.S. government nutrition reference · 2022 · Serum/RBC folate status and homocysteine context · Verified: Aug 12, 2026
Homocysteine Test — U.S. National Library of Medicine (MedlinePlus)
Government medical reference · 2025 · Homocysteine relation to B vitamins, confounders and testing limitations · Verified: Aug 12, 2026