Vitamin D Binding Protein (Serum) – Quantitative Measurement
This test measures the concentration of a protein in your blood that helps transport vitamin D. It’s not directly used for vitamin D levels but may be checked alongside other vitamin D-related tests.
["This test helps assess how your body handles vitamin D, though it’s not a primary screening for vitamin D deficiency."]
Key facts at a glance
- LOINC
- 101976-9
- Short code
- VGCC-P/Q Bind Ab Ser IA-mCnc
- Synonyms
- VGCC-P/Q Bind Ab Ser IA-mCnc
- Category
- electrolyte
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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
What Does This Test Measure?
Vitamin D Binding Protein (VDBP) is a globulin protein found in your blood that binds to vitamin D and other fat-soluble vitamins. It helps transport these substances through your bloodstream. While VDBP itself isn’t directly linked to vitamin D deficiency, it can be part of a broader evaluation if other vitamin-related tests are abnormal.
Why Might Your Doctor Order This Test?
Your doctor may request this test if they suspect conditions affecting vitamin D metabolism, such as kidney disease, liver disease, or certain genetic disorders. It may also be part of a broader panel to evaluate vitamin D status indirectly, especially if other vitamin D-binding proteins or related markers are being assessed.
What Does a Result Mean?
Results are typically reported as a mass concentration in your blood. While reference ranges can vary by lab, higher or lower than expected levels may indicate underlying health conditions that need further evaluation, such as kidney or liver function issues.
What Should You Expect Before the Test?
No special preparation is usually needed. You may have a simple blood draw, similar to other routine blood tests. If you’re on medications or have certain health conditions, let your doctor know before the test.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
While VDBP itself isn’t a direct indicator of vitamin D deficiency, it plays a role in vitamin D transport. Abnormal levels may suggest conditions affecting protein synthesis, liver or kidney function, or genetic disorders. Your doctor may use this test alongside other markers (like 25-hydroxy vitamin D) to assess overall vitamin D status and related metabolic health.
Short name
Vitamin D Binding Protein (VDBP)
Frequently asked questions
Why is my doctor asking about this test?
No, this test does not directly measure vitamin D levels. It assesses the protein that helps transport vitamin D. For vitamin D deficiency, tests like 25-hydroxy vitamin D are typically used instead.
No special diet or fasting is required for this test. You can eat and drink normally before your blood draw, as it’s a standard serum 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 16, 2026. · Read our editorial policy