Serum or plasma concentration of vitamin D (25-hydroxyvitamin D)
This test measures the amount of vitamin D in your blood, which is important for bone health and immune function. Low levels may indicate deficiency, while higher levels could signal overabsorption or certain conditions.
["Vitamin D levels help assess your risk for bone-related issues and overall health."]
Key facts at a glance
- LOINC
- 43004-1
- Short code
- JCV IgG Titr Spec
- Synonyms
- JCV IgG Titr Spec
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 8
- Ref high
- 61
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 82977
- SNOMED
- 3110003
- 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 doctor may order this test if you have symptoms like muscle weakness, bone pain, or frequent infections. It’s also used to check for vitamin D deficiency, which can happen if you don’t get enough sunlight, have limited sun exposure, or have certain medical conditions.
Who Might Need This Test?
People at higher risk for deficiency—such as older adults, those with limited sun exposure, or those with conditions like obesity, kidney disease, or malabsorption disorders—may need this test. Pregnant women, individuals with osteoporosis, or those with autoimmune diseases may also be tested.
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 blood draw if your test includes a fasting component. Bring any medications you’re currently taking to your appointment.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. The sample is sent to a lab for analysis, where vitamin D levels are measured using a blood test method like immunoassay or chemiluminescence.
Reference range
Adult males: 8-61 U/L; Adult females: 5-36 U/LN/A
No special preparation required. Avoid fatty meals before the test if possible.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Short name
Vitamin D level
Frequently asked questions
What are the typical reference ranges for vitamin D?
Can vitamin D levels change over time?
Is vitamin D testing covered by insurance?
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