Serum or plasma concentration of vitamin D (25-hydroxyvitamin D)
This test measures the amount of vitamin D in your blood, which helps your body absorb calcium and maintain strong bones. Low levels may indicate deficiency, which can affect bone health and other body functions.
["Vitamin D levels help prevent deficiencies that could lead to health issues like bone weakness or muscle pain."]
Key facts at a glance
- LOINC
- 24316-2
- Short code
- EBV VCA IgG+IgM Pnl Ser
- Synonyms
- EBV VCA IgG+IgM Pnl Ser
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82784
- 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 Is This Test Done?
Your healthcare provider may order this test if you have symptoms like muscle weakness, bone pain, or if you’re at higher risk for vitamin D deficiency (e.g., limited sun exposure, certain medical conditions, or dietary habits). It’s also used to monitor treatment for conditions like osteoporosis or rickets.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for 8–12 hours before the draw if your lab uses a specific method. Wear comfortable clothing for easy access to your arm.
How the Test Works
A small needle will draw blood from a vein in your arm. The blood sample is sent to a lab to measure vitamin D levels using an immunoassay or similar method to detect and quantify the vitamin.
What the Results Mean
Results are compared to general reference ranges, but your doctor will interpret them in the context of your health history and symptoms. Very low levels may require supplements or lifestyle changes.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Vitamin D is essential for bone health, immune function, and muscle movement. Low levels can lead to conditions like osteomalacia (adult bone softening) or rickets (in children). High levels may indicate over-supplementation or liver/kidney issues, so follow your provider’s guidance.
Short name
Vitamin D level
Frequently asked questions
How often should I get this test?
What are the typical reference ranges for vitamin D?
Can I take vitamin D supplements if my levels are low?
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