Serum or plasma mass 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. Low levels may indicate deficiency, while high levels could signal overabsorption or certain medical conditions.
["Vitamin D levels help assess bone health and prevent deficiencies linked to conditions like osteoporosis or rickets."]
Key facts at a glance
- LOINC
- 22418-8
- Short code
- MuV IgM Ser Ql
- Synonyms
- MuV IgM Ser Ql
- 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 doctor may order this test if you have symptoms like muscle weakness, bone pain, or if you’re at higher risk for vitamin D deficiency—such as living far from the equator, having limited sun exposure, or having certain medical conditions (e.g., malabsorption disorders). It’s also part of routine check-ups for older adults or those with chronic illnesses.
What to Expect Before the Test
No special preparation is needed, but you may be asked to fast for 8–12 hours before the draw if your lab requires it. Wear comfortable clothing and bring your medical records if you have any conditions that affect vitamin D levels.
During the Test
A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but the process is quick and usually painless. The blood sample is sent to a lab for analysis.
What the Results Mean
Results are reported in nanograms per milliliter (ng/mL) or picomoles per liter (pmol/L), but exact ranges depend on your lab. Low levels may prompt further testing or dietary/supplement adjustments, while very high levels could require medical evaluation.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Vitamin D deficiency is linked to weakened bones, muscle weakness, and increased infection risk. High levels may indicate over-supplementation or liver/kidney issues. Your doctor will interpret results in the context of your health history and symptoms.
Short name
Vitamin D level
Frequently asked questions
How long does it take to get my results?
What causes vitamin D deficiency?
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