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Retinol-binding protein (RBP) concentration

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

This test measures the level of retinol-binding protein, a protein in your blood that helps transport vitamin A. Low levels may indicate vitamin A deficiency or liver disease.

Quick summary

["Your RBP level helps assess vitamin A status and liver function."]

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

Key facts at a glance

LOINC
48706-6
Short code
RMV Retic
Synonyms
RMV Retic
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why This Test Is Done

Doctors may order this test to check for vitamin A deficiency, which can affect vision, immune function, and skin health. It may also be used to evaluate liver health or diagnose conditions like nephrotic syndrome, where protein is lost in urine.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into a vein in your arm to draw blood. If you’re concerned about needles, let your healthcare provider know.

What the Results Mean

Results are interpreted by your doctor based on your overall health and symptoms. Very low levels might suggest liver problems or kidney disease, while very high levels could indicate certain infections or inflammatory conditions.

Common Conditions Linked to RBP Levels

Low RBP levels are sometimes seen in vitamin A deficiency, liver disease (like cirrhosis), or kidney disease. High levels may be linked to infections, inflammation, or certain medications.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical significance: RBP is a marker for vitamin A transport and liver function. Abnormal levels can signal underlying health issues that may require further testing or treatment.

Short name

RBP

Frequently asked questions

What causes vitamin A deficiency?
Vitamin A deficiency can result from poor diet (low intake of foods like carrots, sweet potatoes, or liver), malabsorption issues (e.g., celiac disease), or conditions affecting liver/kidney function. Rarely, it may also be due to genetic disorders.
How can I support healthy vitamin A levels?
Eat a balanced diet rich in vitamin A (e.g., leafy greens, fruits, and animal products). If you suspect deficiency, your doctor may recommend supplements or dietary changes. Avoid excessive alcohol, as it can harm liver function.
Is RBP testing painful?
Most people experience only mild discomfort during blood drawing. If you have a hard time with needles, ask your doctor about alternatives like a less painful site or a smaller needle.
  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