Serum Vitamin D (25-hydroxyvitamin D) concentration
This test measures the amount of vitamin D in your blood, which is important for bone health, immune function, and overall well-being. Low levels may indicate deficiency, which can affect how your body absorbs calcium and supports muscle and nerve function.
["Vitamin D helps your body use calcium and phosphorus to build strong bones and supports immune health."]
Key facts at a glance
- LOINC
- 110974-3
- Short code
- LASV IgM Msmt Ser
- Synonyms
- LASV IgM Msmt 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 of vitamin D deficiency, such as muscle weakness, bone pain, or frequent illnesses. It may also be recommended for people at higher risk, including those with limited sun exposure, certain medical conditions, or those taking medications that interfere with vitamin D absorption.
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 test if your lab uses a specific protocol. Wear comfortable clothing and plan to stay near the testing site for about 15 minutes while blood is drawn.
What Happens During the Test?
A healthcare professional will insert a small needle into a vein in your arm to draw blood. You may feel a slight pinch, but it usually doesn’t cause significant discomfort. The blood sample is then sent to a lab for analysis.
What Are the Results?
Results are typically reported as a numerical value representing the concentration of vitamin D in your blood. Your provider will interpret the results in relation to your health status and may recommend adjustments to diet, supplements, or lifestyle if needed.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Vitamin D plays a critical role in preventing bone diseases like osteoporosis, supporting immune function, and potentially reducing the risk of certain chronic conditions. Low levels may lead to weakened bones, increased infection risk, or other health issues. High levels can sometimes cause symptoms like nausea, fatigue, or kidney problems, so monitoring is important.
Short name
Vitamin D Level (Serum)
Frequently asked questions
How long does it take to get my vitamin D test results?
Can I eat or drink anything before my vitamin D blood test?
What does a low vitamin D level mean?
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