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 other bodily functions.
["Vitamin D levels help ensure you have enough of this essential nutrient for overall health."]
Key facts at a glance
- LOINC
- 71762-9
- Short code
- RV IgA Ser Ql IA
- Synonyms
- RV IgA Ser Ql IA
- 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 Is This Test Done?
Your healthcare provider may order this test to check if you have enough vitamin D, especially if you have symptoms like muscle weakness, bone pain, or a history of conditions like osteoporosis or rickets. It can also be used to monitor vitamin D levels if you’re taking supplements or have certain medical conditions that affect vitamin D metabolism.
What Does a Low or High Level Mean?
Low levels of vitamin D may indicate insufficient sun exposure, poor diet, or conditions that interfere with vitamin D absorption. High levels can sometimes be due to overuse of supplements or certain medical treatments.
How Is the Test Performed?
A blood sample is taken from a vein in your arm. The blood is then sent to a lab where it is analyzed to measure vitamin D levels using a specialized immunoassay method.
What Are Common Causes of Abnormal Results?
Abnormal vitamin D levels can result from limited sun exposure, dietary deficiencies, certain digestive disorders, kidney or liver problems, or even medications that affect vitamin D absorption.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Vitamin D is crucial for maintaining bone health, immune function, and muscle strength. Low levels can lead to conditions like osteoporosis or muscle weakness, while very high levels may cause health issues like kidney stones or calcium deposits in soft tissues.
Short name
Vitamin D level
Frequently asked questions
What are the typical reference ranges for this test?
How long does it take to get the results of this test?
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