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Serum or plasma concentration of vitamin D (25-hydroxyvitamin D)

Published: August 9, 2026Updated: August 16, 2026

This test measures your body’s level of vitamin D, which is important for bone health and overall well-being.

Quick summary

["Vitamin D helps maintain strong bones and supports immune function."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
95239-0
Short code
HDV IgM Pnl Ser
Synonyms
HDV IgM Pnl Ser
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 healthcare provider may order this test to check if you have enough vitamin D. This can be important if you have symptoms like muscle weakness, bone pain, or if you’re at higher risk for deficiency (e.g., limited sun exposure, certain medical conditions, or dietary restrictions). It may also be used to monitor treatment for conditions like osteoporosis or rickets.

What to Expect Before the Test

No special preparation is usually needed. You may have a blood sample drawn from a vein in your arm. If you’re taking blood from a finger, you might need to fast for a few hours before the test.

What Happens During the Test?

A healthcare professional will collect a small amount of blood, either from a vein or a finger. The blood will be sent to a lab for analysis. The test typically takes a few minutes to complete.

What Are the Results?

Results will show your vitamin D level in nanograms per milliliter (ng/mL) or picomoles per liter (pmol/L). Your provider will interpret the results based on your health and medical history.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Low vitamin D levels can lead to weakened bones, increased risk of fractures, or other health issues like fatigue or weakened immunity. High levels may not always cause symptoms but can sometimes indicate kidney or liver problems. Regular monitoring helps manage these risks effectively.

Short name

Vitamin D level

Frequently asked questions

What causes vitamin D deficiency?
Vitamin D deficiency can result from limited sun exposure, poor diet (low intake of fatty fish, fortified foods, or supplements), certain medical conditions (like malabsorption disorders), or taking certain medications that interfere with vitamin D absorption.
How long does it take to get results?
Results are usually available within a few days to a week, depending on your lab’s processing time. Your provider will contact you once they have the results.
Can vitamin D levels be affected by medications?
Yes, some medications—such as anticonvulsants, certain antibiotics, or thyroid medications—can lower vitamin D levels. Always discuss your medications with your healthcare provider if you have concerns.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

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.

Medical Disclaimer

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