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Phosphoserine/Creatinine Ratio, 24-Hour Urine

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

Measures urinary phosphoserine relative to creatinine over 24 hours, helping assess phosphoserine excretion while accounting for urine concentration.

Quick summary

["This test measures how much phosphoserine is excreted in urine compared with creatinine."]

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

Key facts at a glance

LOINC
25974-7
Short code
Phosphoserine/Creat 24h Ur-sRto
Synonyms
Phosphoserine/Creat 24h 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 the amount of phosphoserine, a form of the amino acid serine, excreted in urine over 24 hours. The result is reported relative to urinary creatinine, which helps account for differences in urine concentration.

Why might I need this test?

A clinician may order this test to evaluate phosphoserine metabolism, investigate unusual urinary excretion, or monitor a condition or treatment affecting amino acid handling. It may be part of a broader evaluation for nutritional, metabolic, or kidney-related concerns.

How is the test performed?

All urine produced during a full 24-hour period is collected in a special container. The laboratory measures phosphoserine and creatinine and calculates their ratio.

How do I prepare for the test?

Follow the collection instructions provided by your healthcare professional, including the specified start and end times. Do not deliberately change your diet, fluid intake, or medications unless your clinician instructs you to do so.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

24-Hour Urine Phosphoserine/Creatinine Ratio

Frequently asked questions

What does the phosphoserine/creatinine ratio measure?
It compares the amount of phosphoserine excreted in urine with the amount of creatinine. Creatinine is used as a reference to help account for variations in urine concentration.
Why is a 24-hour urine collection needed?
Collecting all urine for 24 hours provides a more complete measure of daily phosphoserine excretion than a single urine sample. Correct timing and complete collection are important for reliable results.
Does an abnormal result confirm a specific disease?
No. An abnormal ratio can have several causes and is usually interpreted alongside the rest of your medical evaluation. Your healthcare professional can explain the result in the context of your symptoms and other tests.
  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