Vitamin D
supplementAn essential vitamin for bones and muscles; worth testing before you supplement.
17 providers
Lab test
What is a vitamin D test, and what is a normal vitamin D level?
A vitamin D test measures 25-hydroxyvitamin D, the main form that shows vitamin D status. It is ordered when a bone or other condition may relate to low vitamin D, not routinely for everyone. Cutoffs differ: the National Academies call 20 ng/mL or more sufficient for most people, while ARUP labels 30 to 80 ng/mL optimal.
What does the vitamin D test measure?
Serum 25-hydroxyvitamin D (25(OH)D) is the main indicator of vitamin D status; it reflects vitamin D made in the skin and obtained from foods and supplements. NIH Office of Dietary Supplements
Results may be reported as total vitamin D, or as vitamin D2 and D3 separately; total vitamin D is the number to check. MedlinePlus
Why is the vitamin D test ordered?
- When a provider thinks a bone or other condition could be caused by very low vitamin D, such as osteomalacia, osteoporosis or rickets. MedlinePlus
- For people at high risk of deficiency. MedlinePlus notes routine testing is not recommended for everyone. MedlinePlus
What are typical vitamin D ranges?
Published cutoffs for vitamin D differ, so two sources are shown side by side. NIH Office of Dietary Supplements
Reference ranges differ between laboratories and testing methods, and many also differ by age, sex, pregnancy or the phase of the menstrual cycle. The range printed on your own report is the one that applies to your result, and a clinician interprets it alongside your history.
| Level | Described as |
|---|---|
| Less than 12 ng/mL | Associated with vitamin D deficiency |
| 12 to under 20 ng/mL | Generally considered inadequate for bone and overall health |
| 20 ng/mL or more | Generally considered adequate for most people |
| More than 50 ng/mL | Linked to potential adverse effects |
| Category | Level |
|---|---|
| Deficiency | Less than 20 ng/mL |
| Insufficiency | 20 to 29 ng/mL |
| Optimum level | 30 to 80 ng/mL |
| Possible toxicity | Greater than 150 ng/mL |
The NIH Office of Dietary Supplements notes that the levels associated with deficiency have not been definitively identified, and that the Endocrine Society does not recommend routine testing in healthy people. NIH Office of Dietary Supplements
What can affect vitamin D results?
- No special preparation is needed, but vitamins, supplements and medicines may affect results, so tell your provider what you take. MedlinePlus
- Labs report in ng/mL or nmol/L; 20 ng/mL equals 50 nmol/L, so check the unit before comparing numbers. NIH Office of Dietary Supplements
When should you talk to a clinician about a vitamin D result?
- Ask your provider whether a vitamin D test is right for you, and what a result means given your bone health and risk factors. MedlinePlus
DiscoverMedica explains what a test measures and what named sources publish. It does not interpret individual results; the clinician who ordered your test, or one you choose, does.
Where can you get a vitamin D test?
A clinician can order it as part of routine or follow-up care. Some services also let you order lab tests yourself; check that a service’s panel includes this marker, which laboratory runs it, and who reviews the result with you.
- Function HealthAnnual membership for broad lab panels, drawn at Quest sites or at home.
- Quest HealthOrder individual lab tests from Quest Diagnostics online, without a doctor’s visit. Lists “Vitamin D (25-hydroxy D2 and D3) blood test” at $75.00, as listed on its site, checked September 23, 2026.
Vitamin D (25-Hydroxy) Test: questions, answered
What is a normal vitamin D level?
Sources differ. The National Academies, as summarized by the NIH Office of Dietary Supplements, consider 20 ng/mL (50 nmol/L) or more adequate for most people. ARUP Laboratories labels 20 to 29 ng/mL insufficient and 30 to 80 ng/mL optimal for adults. Your report prints the categories your lab uses.
Who should get a vitamin D test?
MedlinePlus says routine testing is not recommended for everyone. A provider may order it for conditions linked to low vitamin D, such as osteoporosis, or for people at high risk of deficiency. The Endocrine Society also does not recommend routine testing in healthy people.
Can vitamin D be too high?
Yes. The NIH Office of Dietary Supplements notes that levels above 50 ng/mL (125 nmol/L) have been linked to potential adverse effects, and ARUP flags levels above 150 ng/mL as possible toxicity. Tell your clinician about any supplements you take.
Sources
- MedlinePlus: Vitamin D Test
- NIH Office of Dietary Supplements: Vitamin D, Fact Sheet for Health Professionals
- ARUP Laboratories: Vitamin D, 25-Hydroxy (test 0080379)
Last reviewed October 7, 2026. Every source above was checked on or before that date. Educational information only, not medical advice; it does not replace a conversation with a licensed clinician. DiscoverMedica does not employ clinicians.
Options people research alongside this test
Listed for context only. Whether any of them suits you is a decision to make with a clinician.