Understanding Your Laboratory Test: A Patient's Guide
This blood test measures the levels of 24,25-dihydroxyvitamin D, a metabolite of vitamin D that provides additional information about vitamin D metabolism and kidney function.
{"The test measures 24,25-dihydroxyvitamin D (both D3 and D2 forms) in blood","It helps evaluate how well the body processes vitamin D","Results can indicate kidney function and vitamin D status","A small blood sample is taken from a vein in your arm","Results are typically available within a few days"}
Key facts at a glance
- LOINC
- 94672-3
- Short code
- 24,25(OH)2D
- Synonyms
- 24,25(OH)2 VitD SerPl-mCnc
- Category
- chemistry
- Sample
- serum
- Container
- Serum separator tube (SST) or plain red top tube
- Units
- N/A
- Ref low
- 2
- Ref high
- 14
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- ≥ 0 years
- Method
- Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
- CPT
- 82352
- SNOMED
- 371468004
- Specimen volume
- 1.0-2.0 mL of serum
- Stability
- Room temperature: 24 hours; Refrigerated (2-8°C): 7 days; Frozen (-20°C or below): 30 days. Protect from light.
- Hemolysis max
- 50
- Lipemia max
- 300
- Icterus max
- 20
- TAT
- 48–168 hours
- Order
- routine
This test measures specific substances in your body to help your healthcare provider evaluate your overall health. It may involve a small sample of blood, urine, or another specimen that is analyzed in a laboratory to detect, monitor, or rule out medical conditions.
The 24,25-dihydroxyvitamin D test measures the amount of 24,25-dihydroxyvitamin D in your blood. This is a specific form of vitamin D that is produced when your body processes vitamin D through the kidneys. The test measures both 24,25-dihydroxyvitamin D3 (from animal-based vitamin D) and 24,25-dihydroxyvitamin D2 (from plant-based vitamin D).
Your doctor may order this test as part of a routine checkup, to help diagnose the cause of symptoms you are experiencing, to monitor an ongoing condition, or to see how well a treatment is working. The results provide important information that guides decisions about your care.
This test may be ordered to: evaluate kidney function and how well the kidneys are converting vitamin D; assess vitamin D metabolism disorders; help diagnose conditions affecting vitamin D processing; monitor patients with chronic kidney disease; and sometimes to differentiate between different causes of abnormal calcium levels.
The test is usually performed in a clinic, laboratory, or hospital. A trained technician will collect the required sample, often by drawing a small amount of blood from a vein in your arm using a thin needle. The procedure takes only a few minutes, and you may feel a brief pinch. Afterward, your sample is sent to a laboratory for analysis.
A healthcare professional will draw a small sample of blood from a vein in your arm using a needle. The blood is collected into a tube and sent to a laboratory for analysis. You do not need to fast before this test in most cases, but follow any specific instructions from your healthcare provider.
Your results will show your measured values next to a reference range, which represents the levels typically seen in healthy people. Values outside this range do not always mean you have a medical problem, so it is important to review the report with your healthcare provider, who can explain what the numbers mean for you and whether any follow-up testing is needed.
Normal ranges for 24,25-dihydroxyvitamin D vary by laboratory. Your results will be interpreted by your healthcare provider considering your overall health, other test results, and specific medical conditions. Both low and high levels can provide important information about your health.
Reference range
Reference range: 2.0-14.0 ng/mL (combined 24,25-dihydroxyvitamin D3 and D2). The 24,25-dihydroxyvitamin D to 25-hydroxyvitamin D ratio may provide additional clinical information.N/A
No special preparation required. Fasting is not mandatory. Inform the laboratory of any vitamin D supplements or medications that may affect vitamin D metabolism.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low levels of 24,25-dihydroxyvitamin D may indicate kidney disease or impairment, vitamin D deficiency, certain genetic disorders affecting vitamin D metabolism, or problems with the enzymes needed to convert vitamin D. High levels may occur with certain conditions or excessive vitamin D supplementation. This test provides valuable information beyond the standard 25-hydroxyvitamin D test by showing how well the body is actually using vitamin D.
Frequently asked questions
How is this different from the standard vitamin D test?
Do I need to prepare for this test?
What do low results mean?
Is this test safe?
Sources
- 1
- 2
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