Serum or plasma concentration of vitamin D (25-hydroxyvitamin D)
This test measures your body’s level of vitamin D, an essential nutrient that helps your bones stay strong and supports other important health functions.
["Vitamin D levels help assess your risk for deficiencies and related health issues."]
Key facts at a glance
- LOINC
- 49539-0
- Short code
- CMV IgM SerPl Ql IF
- Synonyms
- CMV IgM SerPl Ql IF
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- if
- 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 Is Done
Your healthcare provider may order this test if you have symptoms of vitamin D deficiency, such as muscle weakness, bone pain, or frequent infections. It may also be recommended for people with limited sun exposure, certain medical conditions (like kidney or liver disease), or those taking medications that affect 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 blood is drawn in the morning. Wear comfortable clothing and plan to stay near the testing site for a short time.
How the Test Is Performed
A healthcare professional will draw blood from a vein in your arm using a small needle. You may feel a slight sting, but the procedure is quick and typically doesn’t cause long-lasting discomfort.
What the Results Mean
Results are compared to standard reference ranges, but exact values can vary by lab. Low levels may indicate deficiency, while higher levels could signal overabsorption or certain medical conditions. Your provider will interpret results in the context of your overall health.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Clinical Significance
Short name
Vitamin D level
Frequently asked questions
Vitamin D deficiency is linked to weakened bones, increased infection risk, and other health problems. Regular monitoring helps prevent complications and guides treatment if needed.
What if my results are low? If your vitamin D level is below normal, your doctor may recommend increasing sun exposure, dietary changes, or supplements to help restore balance.
Does diet affect this test? Foods rich in vitamin D (like fatty fish, fortified dairy, or egg yolks) may influence results, so avoid large changes to your diet before testing.
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