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5-Alpha-Tetrahydrofolate (5a-THF), 24-Hour Urine — Mass Rate

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

Measures 5-alpha-tetrahydrofolate excreted in urine over 24 hours, reported as the amount eliminated per unit of time.

Quick summary

["This test measures urinary excretion of a reduced folate compound and is interpreted along with diet, supplement use, and other folate tests."]

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

Key facts at a glance

LOINC
57618-1
Short code
5-A THF Pre Dex 24h Ur-mRate
Synonyms
5-A THF Pre Dex 24h Ur-mRate
Category
liver
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What is this test?

This test measures 5-alpha-tetrahydrofolate, also called 5a-THF, in urine collected for 24 hours. The result is reported as a mass rate, which shows how much of the compound is excreted over time.

Why might I need this test?

A 24-hour urine measurement may be used to evaluate folate metabolism and the amount of this folate compound being lost in the urine. It may be ordered alongside dietary information, supplement use, blood folate tests, or tests for vitamin B12.

How is the test performed?

Urine is collected for a full 24-hour period, usually in a labeled container provided by the laboratory. The total urine volume and collection time are recorded so the laboratory can calculate the result.

How do I prepare for the test?

Follow the laboratory's collection instructions and record when the collection starts and ends. Tell the healthcare provider about folic acid or multivitamin supplements, because supplements and dietary changes can affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A higher or lower amount may reflect differences in folate intake, supplement use, intestinal absorption, metabolism, or urinary excretion. This test is not usually interpreted by itself and should be considered with symptoms, medications, and other laboratory results.

Short name

24-Hour Urine 5a-THF

Frequently asked questions

What does a 24-hour urine test show?
It shows the total amount of a substance excreted in the urine during one day. Recording the collection time and total volume allows the laboratory to report the result per unit of time.
Do I need to stop taking vitamins before this test?
Do not stop supplements unless your healthcare provider instructs you to do so. Tell the laboratory about folic acid, multivitamins, and other supplements because they may affect the result.
Can a urine result diagnose a vitamin deficiency?
No single result usually establishes a deficiency. The healthcare provider will interpret urinary 5a-THF together with blood tests, diet, supplement use, symptoms, and other relevant findings.
  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