Iron/Creatinine Ratio, 24-Hour Urine
Measures iron relative to creatinine in urine collected for 24 hours. The ratio helps account for variations in urine concentration.
["This test estimates how much iron is being lost in the urine while adjusting for urine concentration."]
Key facts at a glance
- LOINC
- 57014-3
- Short code
- Iron/Creat 24h Ur
- Synonyms
- Iron/Creat 24h Ur
- Category
- kidney
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 60
- Ref high
- 170
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 83540
- 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 iron in a 24-hour urine collection and compares it with the amount of creatinine. Creatinine is used as a marker of urine concentration, so the ratio can help interpret the iron measurement even when urine concentration varies.
Why might I need this test?
Your clinician may order this test to evaluate iron excretion, particularly when there is concern about iron overload, an iron-related disorder, or excess iron loss through the urine. It may also be used alongside other iron studies, blood tests, and genetic or imaging results.
How is the test performed?
You collect all urine for a full 24-hour period, usually beginning after emptying your bladder in the morning and ending the following morning. The laboratory then measures iron and creatinine in the collection and calculates the ratio.
How do I prepare for the test?
Follow the collection instructions provided by your clinician or laboratory, including the exact start and stop times and any storage requirements. Tell the healthcare team if you are pregnant, have recently used medicines or supplements that contain iron, or have a condition that affects urine collection.
Reference range
NCBI: Serum Iron Male 65-180; Female 50-170 µg/dLN/A
Fasting for 12 hours preferred. Iron supplements should be stopped 24 hours before if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
A higher iron/creatinine ratio may indicate increased urinary iron excretion, which can occur with iron overload or certain iron-related disorders. A lower ratio may reflect reduced iron excretion or other changes affecting iron handling. Results should be interpreted with the 24-hour urine volume, kidney function, medicines, and other iron tests because the ratio alone does not establish a diagnosis.
Short name
24-hour urine iron/creatinine ratio
Frequently asked questions
Do I need to fast for this test?
What happens if I miss part of the 24-hour urine collection?
Why is creatinine included in this urine test?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
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.
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 17, 2026. · Read our editorial policy