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Vitamin C (Ascorbic Acid)/Creatinine Ratio, Urine

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

Measures urine vitamin C relative to creatinine to help assess vitamin C intake and nutritional status while accounting for urine concentration.

Quick summary

["This urine test estimates vitamin C intake and status, but recent supplementation and urine collection time can strongly affect the result."]

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

Key facts at a glance

LOINC
34248-5
Short code
Vit C/Creat Ur-sRto
Synonyms
Vit C/Creat Ur-sRto
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 test measures vitamin C, also called ascorbic acid, in urine and compares it with the amount of creatinine in the same sample. The ratio helps reduce the effect of differences in urine concentration.

Why might I need this test?

A clinician may use this test as part of a nutritional assessment, particularly for people with limited dietary intake, poor absorption, increased needs, or a risk of vitamin C deficiency.

How is the test performed?

A urine sample is collected and analyzed in a laboratory. The laboratory reports the amount of vitamin C relative to the amount of creatinine in that sample.

How do I prepare for the test?

Follow the collection instructions provided by your clinician or laboratory. Vitamin C supplements and foods or drinks containing vitamin C can raise the result, so do not change your diet or supplements unless instructed to do so.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Urine Vitamin C/Creatinine Ratio

Frequently asked questions

Does this test diagnose scurvy?
No. It may support an assessment of vitamin C status, but scurvy is diagnosed using symptoms, dietary history, and other clinical findings.
Can vitamin C supplements affect the result?
Yes. Supplements and vitamin C-rich foods or drinks can increase urine vitamin C, sometimes for several hours after intake.
Why is the result divided by creatinine?
Creatinine is used as a marker of urine concentration. Dividing by it helps reduce variation caused by how dilute or concentrated the urine sample is.
  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