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 bone health.
["Vitamin D levels help assess your risk for bone-related conditions and overall health."]
Key facts at a glance
- LOINC
- 5403-1
- Short code
- VZV IgG Ser IA-aCnc
- Synonyms
- VZV IgG Ser IA-aCnc
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- ia
- 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 This Test Matters for Your Health
Vitamin D is essential for bone health, immune function, and muscle strength. Low levels may increase your risk of osteoporosis, muscle weakness, or certain infections. Your doctor may recommend this test if you have symptoms like bone pain, frequent infections, or if you’re at higher risk due to limited sun exposure, certain diets, or medical conditions.
What to Expect Before the Test
No special preparation is needed. You may have blood drawn from a vein in your arm. If you’re taking vitamin D supplements, your doctor may advise stopping them for a few days before testing to get an accurate result.
What the Results Mean
Results are typically reported as a numeric value indicating the concentration of vitamin D in your blood. Your doctor will interpret these results in relation to your overall health and symptoms.
Common Reasons for Testing
Doctors may order this test if you have symptoms like fatigue, muscle pain, or bone pain; if you have conditions like osteoporosis or rickets; or if you have limited sun exposure, certain diets (e.g., vegan), or medical conditions affecting vitamin D absorption.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Vitamin D deficiency is common and can lead to serious health issues, including weakened bones, increased infection risk, and even certain chronic diseases. Regular monitoring helps manage conditions like osteoporosis, muscle weakness, or autoimmune disorders. Your doctor will use these results to guide treatment, such as supplements or lifestyle changes.
Short name
Vitamin D Level
Frequently asked questions
What causes vitamin D deficiency?
How long does it take to get results?
Can I take vitamin D supplements without checking my levels first?
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