Retinol-binding protein mass concentration (serum/plasma)
This test measures the amount of retinol-binding protein in your blood, which helps transport vitamin A. It may be used to assess liver function, vitamin A status, or kidney function.
["RBP levels can indicate how well your body is using vitamin A or if there’s a problem with your liver or kidneys."]
Key facts at a glance
- LOINC
- 33782-4
- Short code
- Retinol Bind Prot Ur-mCnc
- Synonyms
- Retinol Bind Prot Ur-mCnc
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 38
- Ref high
- 98
- 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
Why Might This Test Be Ordered?
Your healthcare provider may order this test if you have symptoms like fatigue, vision changes, or unexplained weight loss. It could also be part of a broader evaluation for liver disease, kidney problems, or vitamin A deficiency. Some conditions, like nephrotic syndrome or certain liver disorders, can affect RBP levels.
What Does a Low or High Level Mean?
Low levels of RBP might suggest liver disease, kidney problems, or vitamin A deficiency. High levels could be linked to conditions like nephrotic syndrome, where the kidneys lose too much protein into urine.
How Is This Test Performed?
A blood sample is drawn from a vein, usually in your arm. The sample is sent to a lab where it’s analyzed using a specialized technique to measure RBP concentration.
What Are Common Causes of Abnormal Results?
Abnormal RBP levels can result from liver disease (such as cirrhosis), kidney disease, vitamin A deficiency, or certain genetic conditions. Rarely, it may also be affected by medications or pregnancy.
Reference range
NCBI: Vitamin A 38-98 µg/dLN/A
No special preparation usually required. Stay well hydrated. Inform your healthcare provider of all medications and supplements you are taking.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance: When This Test Matters
Short name
Retinol-binding protein (RBP) level
Frequently asked questions
When would you need to discuss abnormal results with your doctor?
How often should I expect this test?
What should I do if I have concerns about my results?
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