25ohd3serplmscnc
A blood test that measures the level of 25-hydroxyvitamin D in your blood to evaluate vitamin D status.
{"Measures the main form of vitamin D in the blood","Helps diagnose vitamin D deficiency or excess","Sample is collected from a vein in your arm","Results help guide supplementation and treatment","Abnormal levels may indicate bone, kidney, or parathyroid issues"}
Key facts at a glance
- LOINC
- 35196-5
- Short code
- 25-OH Vitamin D, 25-Hydroxyvitamin D, Vit D, 25(OH)D
- Synonyms
- 25(OH)D3 SerPl-msCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum Separator Tube (SST/Gold top) or Red top tube
- Units
- N/A
- Ref low
- 30
- Ref high
- 100
- Critical range
- 10 N/A – 150 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Chemiluminescence Immunoassay (CLIA) or Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 82306
- SNOMED
- 368009
- Specimen volume
- 1.0-2.0 mL serum minimum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Protect from light exposure.
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 20
- TAT
- 24–72 hours
- Order
- routine
What is this test?
The 25-hydroxyvitamin D test measures the amount of 25-hydroxyvitamin D in your blood. This is the major form of vitamin D stored in the body and is considered the best indicator of your overall vitamin D status. Vitamin D is essential for maintaining healthy bones, supporting the immune system, and regulating calcium and phosphorus absorption.
Why do I need this test?
Your healthcare provider may order this test if you have symptoms of vitamin D deficiency such as bone pain, muscle weakness, or fatigue. It is also used to monitor people at risk for vitamin D deficiency, including those with limited sun exposure, certain digestive disorders, kidney disease, or osteoporosis. The test helps determine if you need vitamin D supplements or if your current treatment is working effectively.
How should I prepare?
Generally, no special preparation is needed for this test. You may eat and drink normally unless your healthcare provider gives you other instructions. Certain medications and supplements can affect test results, so inform your doctor about all medications and vitamins you are taking. The test requires a simple blood draw, so wearing a short-sleeved shirt can make the process easier.
What happens during the test?
A healthcare professional will clean the skin on your arm with an antiseptic and wrap an elastic band around your upper arm to make the veins more visible. A needle will be inserted into a vein, and blood will be collected into a tube. You may feel a brief pinch or sting. The entire process usually takes only a few minutes. After the blood is collected, the needle is removed, and pressure is applied to stop any bleeding.
What do the results mean?
Vitamin D levels are typically measured in nanograms per milliliter (ng/mL) or nanomoles per liter (nmol/L). Generally, levels below 20 ng/mL (50 nmol/L) indicate vitamin D deficiency, while levels between 20-30 ng/mL (50-75 nmol/L) may be considered insufficient. Levels of 30-100 ng/mL (75-250 nmol/L) are usually considered adequate for most people. Your healthcare provider will interpret your results based on your overall health, symptoms, and other test results.
Reference range
Sufficient: 30-100 ng/mL (75-250 nmol/L); Insufficient: 20-29 ng/mL (50-74 nmol/L); Deficient: <20 ng/mL (<50 nmol/L); Toxicity: >150 ng/mL (>375 nmol/L)N/A
No fasting required. Collect preferably in the morning. Avoid excessive hemolysis. Inform about supplements containing vitamin D as they may affect results.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
◆Associated findings1
Frequently asked questions
How long does it take to get results?
Are there any risks with this test?
Can I take vitamin D supplements before the test?
What happens if my vitamin D levels are low?
How often should I have this test?
Sources
- 1
- 2Mayo Clinic - Vitamin DSource
- 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 10, 2026. · Read our editorial policy