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Tetrahydrofolate/Creatinine [Mass Ratio] in Urine

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

Measures urinary tetrahydrofolate relative to creatinine, helping assess folate excretion while accounting for urine concentration.

Quick summary

["The result reflects urinary folate excretion relative to creatinine and should be interpreted with diet, supplement use, and urine collection details."]

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

Key facts at a glance

LOINC
50645-1
Short code
THF/Creat Ur
Synonyms
THF/Creat Ur
Category
kidney
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 urine test measures tetrahydrofolate, an active form of folate, and compares it with the amount of creatinine in the same sample. Creatinine is used to adjust for differences in urine concentration.

Why might I need this test?

A clinician may use this test to assess folate excretion or investigate possible differences in folate intake or absorption. It may also be used when monitoring people with conditions or medicines that can affect folate status.

How is the test performed?

A urine specimen is collected according to the laboratory's instructions, either as a spot sample or over a specified period. The laboratory measures tetrahydrofolate and creatinine and calculates their ratio.

How do I prepare for the test?

Follow the laboratory's collection instructions and tell the care team about folate supplements and multivitamins. Do not stop medicines or change your diet without medical advice, because recent intake and supplement use can affect the result.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

A low tetrahydrofolate/creatinine ratio may be associated with low folate intake, impaired absorption, increased folate needs, or certain medicines. A higher ratio may reflect recent folate-rich meals or supplement use. Results should be interpreted with the collection method, kidney function, diet, and medication history.

Short name

Urine tetrahydrofolate/creatinine ratio

Frequently asked questions

What does the urine tetrahydrofolate/creatinine ratio show?
It estimates urinary folate excretion relative to urine concentration. This makes the result less dependent on how concentrated or dilute the urine sample is.
Why is this test ordered?
It may be ordered to evaluate folate status or excretion, particularly when intake, absorption, medication use, or increased folate requirements are concerns.
Do supplements or diet affect the result?
Yes. Recent folate-rich foods and supplements can increase urinary folate, so tell the clinician what you have taken and when.
  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