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25ohd3bldcmcnc

Published: August 9, 2026Updated: August 10, 2026

This test measures the level of 25-hydroxyvitamin D3 in a small blood sample from your fingertip to check your vitamin D status.

Quick summary

{"Measures vitamin D level using a small finger-prick blood sample","Helps detect vitamin D deficiency or excess in the body","Important for evaluating bone health, calcium absorption, and immune function","Results guide supplementation and treatment decisions","Fast and simple test that can be done in clinic or at home"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 10, 2026Editorial policy

Key facts at a glance

LOINC
95594-8
Short code
25-OH D3 Cap
Synonyms
25(OH)D3 BldC-mCnc
Category
chemistry
Sample
whole-blood
Container
Capillary blood collection device (microtainer) with appropriate anticoagulant (EDTA or heparin) or serum separator
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
0–120 years
Method
Liquid chromatography-tandem mass spectrometry (LC-MS/MS)
CPT
82306
SNOMED
371371003
Specimen volume
Minimum 100-200 μL of capillary whole blood
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
50
Icterus max
20
TAT
24–72 hours
Order
routine

What is this test?

The 25-hydroxyvitamin D3 test measures the amount of 25-hydroxyvitamin D (also called calcidiol) in your blood. This form of vitamin D is the major circulating form in the body and is considered the best indicator of your overall vitamin D status. The test uses a small sample of capillary blood (whole blood from a fingertip prick).

Why is this test performed?

This test is ordered to: (1) screen for vitamin D deficiency, especially in people at risk such as older adults, those with limited sun exposure, or people with certain digestive conditions; (2) monitor vitamin D levels in patients taking vitamin D supplements; (3) help diagnose conditions related to calcium metabolism like rickets or osteomalacia; and (4) evaluate causes of abnormal calcium levels.

How is the test done?

A healthcare professional will clean your fingertip with an antiseptic wipe and use a small lancet to prick your finger. A few drops of blood are collected into a small container or test strip. The sample is then sent to a laboratory for analysis. The procedure is quick and causes minimal discomfort.

Understanding your results

Results are typically reported in ng/mL or nmol/L. Generally: ≥30 ng/mL (≥75 nmol/L) is considered sufficient; 20-29 ng/mL (50-74 nmol/L) indicates insufficiency; and <20 ng/mL (<50 nmol/L) suggests deficiency. Your healthcare provider will interpret your results based on your overall health and risk factors.

Reference range

Sufficient: 30-100 ng/mL (75-250 nmol/L); Insufficient: 20-29 ng/mL (50-72 nmol/L); Deficient: <20 ng/mL (<50 nmol/L); Toxic: >100 ng/mL (>250 nmol/L)N/A

Specimen: whole-blood

No fasting required. Collect capillary blood using proper microcollection techniques. Ensure adequate warming of puncture site to promote blood flow. Avoid excessive squeezing of fingertip which may contaminate sample with tissue fluid.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

Do I need to fast before this test?
No fasting is required for the 25-hydroxyvitamin D3 test. You can eat and drink normally before the test.
How long does it take to get results?
Results are usually available within a few days to a week, depending on the laboratory.
What can cause low vitamin D levels?
Low vitamin D can be caused by limited sun exposure, dark skin, being elderly, obesity, certain digestive diseases (like Crohn's or celiac disease) that impair fat absorption, kidney or liver disease, and dietary deficiency.
Can I take vitamin D supplements before the test?
Follow your healthcare provider's instructions. If you are already taking supplements, tell your doctor as this may affect your test results.
What happens if my vitamin D is too high?
Excess vitamin D (toxicity) is rare but can occur from taking too many supplements. High levels can cause nausea, vomiting, weakness, and serious complications like kidney problems. Your healthcare provider will advise on appropriate next steps if your levels are elevated.
  1. 1
    MedlinePlus - Vitamin D TestSource
  2. 2
    Mayo Clinic - Vitamin DSource
  3. 3
    LOINC - 25-Hydroxyvitamin D3 [Mass/volume] in Capillary bloodSource

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 10, 2026. · Read our editorial policy