Current promotion
Vitamin D Blood Test: 25-Hydroxy D Levels & Deficiency Screening
A precise look at your 25-hydroxy vitamin D level, the marker doctors use to assess vitamin D status.
Affiliate disclosure: we earn a commission when you purchase lab tests through links on this site, at no extra cost to you. Learn more
Single vitamin D tests from $35.20 and multi-marker panels from $115.16 with the current 20% promotion (pricing at time of writing).
At a glance
Vitamin D deficiency screening measures 25-hydroxyvitamin D, in some versions broken out into its D2 and D3 fractions, from a simple blood draw to show whether your level falls in the deficient, insufficient, adequate, or high range. It is designed for adults who get limited sun exposure, take vitamin D supplements, or want objective data behind fatigue, bone, muscle, or mood-related concerns. Your result gives you and your doctor a concrete number to act on and re-test against over time.
Best suited for
- Adults with limited sun exposure, indoor work, northern latitudes, consistent sunscreen use, or darker skin tones
- People taking vitamin D supplements who want to confirm their dose is keeping levels in range
- Anyone experiencing fatigue, muscle weakness, bone discomfort, or mood changes they plan to discuss with a doctor
- Older adults and people with conditions associated with reduced vitamin D absorption
- Health-conscious people establishing a nutritional baseline to track over time
What's included
Vitamin D 25-Hydroxy Total Test
Single-marker check of total 25-hydroxyvitamin D status
QuestAssureD Vitamin D 25-Hydroxy Total Test with D2 and D3
Breaks total 25-OH vitamin D into its D2 and D3 fractions
Vitamin D Deficiency Discovery Panel
5 tests covering 59 biomarkers for broader context around vitamin D status
Vitamin D Deficiency Discovery Plus Panel
8 tests covering 64 biomarkers
The Ultimate Vitamin D Panel
5 tests covering 8 vitamin D-related biomarkers
Vitamins & Minerals - Basic Plus
Adds ferritin, folate, iron/TIBC, magnesium, prealbumin, transferrin, and B12 alongside vitamin D
Vitamins & Minerals - Advanced
Basic Plus markers plus homocysteine, RBC magnesium, and zinc
Vitamins & Minerals + (Omegas, CMP & CBC) - Basic Plus
Nutrient markers plus omega fatty acids, metabolic panel, and blood count
Vitamins & Minerals + (Omegas, CMP & CBC) - Advanced
14 tests covering 79 biomarkers
Vitamins & Minerals - Comprehensive
24-test broad-spectrum nutritional assessment
Key biomarker ranges
Commonly used adult reference ranges for markers this panel measures, labs vary, so always interpret results against your lab's stated ranges and with your doctor.
Commonly used cutoffs: below 20 ng/mL deficient, 20–30 insufficient, 30–60 a frequently cited target band; season and supplementation move levels substantially.
| Zone | Range |
|---|---|
| Deficient | 0–20 ng/mL |
| Insufficient | 20–30 ng/mL |
| Sufficient | 30–60 ng/mL |
| High | 60–100 ng/mL |
Commonly used reference ranges differ by sex, roughly 30–200 ng/mL is typical, with men’s upper bounds higher; inflammation can raise ferritin and mask low iron.
| Zone | Range |
|---|---|
| Low | 0–30 ng/mL |
| Typical range | 30–200 ng/mL |
| Elevated | 200–400 ng/mL |
The importance of testing
25-hydroxyvitamin D is the standard circulating marker of vitamin D status, and it is the number your doctor looks at when deciding whether your level is on target. Some tests on this page, like the QuestAssureD 25-Hydroxy Total Test, also separate vitamin D2 (typically from fortified foods and some supplements) from D3 (from sunlight and most over-the-counter supplements), which adds useful detail if you are already supplementing.
Vitamin D plays a role in calcium absorption and is associated with bone density, muscle function, immune health, and mood regulation. Levels commonly run low in people with limited sunlight exposure, diets low in vitamin D-rich foods, older age, or certain medical conditions, often without obvious symptoms. Because signs like fatigue, muscle weakness, bone discomfort, and mood changes are nonspecific, testing replaces guesswork with a measurable value you can review with your doctor.
Vitamin D status is also one of the most trackable markers in a wellness routine. A baseline result shows where you stand today; a follow-up test a few months after changing your supplement dose, diet, or sun habits shows whether those changes are actually moving your level. Results at either extreme are worth discussing with your doctor, persistently low values flag possible deficiency, while unexpectedly high values can flag over-supplementation.
If you want wider context, the Discovery panels and the Vitamins & Minerals panels on this page place vitamin D alongside markers like ferritin, vitamin B12, folate, and magnesium, so you can see your vitamin D result within a broader nutritional picture.
Part of our complete guide to Nutrient & Vitamin Lab Tests — browse every panel and biomarker guide in this hub.
Promo code
ULTAFE1BSave 20% with code ULTAFE1B, current promotion; confirm final pricing on the partner page.
Ready to get your numbers? Order online, visit a nearby draw site, and receive private results to review with your doctor.
Order NowFrequently asked questions
What does a vitamin D blood test measure?
A vitamin D blood test measures 25-hydroxyvitamin D, the main circulating form of vitamin D and the standard marker of vitamin D status. Some versions, like the QuestAssureD test, also report the D2 and D3 fractions separately, which can help you and your doctor see whether supplements or diet are contributing to your total level.
Do I need a doctor's visit to order a vitamin D test?
No, these tests can be ordered online without a doctor's visit or separate lab order. You purchase the test through the partner page, complete a blood draw at a local patient service center, and receive your results promptly online. Sharing results with your own doctor is still recommended for interpretation and next steps.
What is the difference between the total 25-hydroxy test and the D2/D3 version?
The total test reports a single combined 25-hydroxyvitamin D value, while the D2/D3 version reports vitamin D2, vitamin D3, and the total separately. The breakdown is most useful if you take prescription vitamin D2 or want to see how much of your level comes from D3 sources like sunlight and common supplements.
What do low vitamin D results mean?
A low result flags possible vitamin D deficiency or insufficiency, which is worth reviewing with your doctor before making changes. Low levels are associated with markers of reduced bone density, muscle weakness, and immune function, and they are common in people with limited sun exposure, lower dietary intake, older age, or certain medical conditions.
How often should I re-test my vitamin D level?
A common approach is to establish a baseline, then re-test roughly three months after starting or adjusting supplements, since 25-hydroxyvitamin D responds gradually to changes. Your doctor can recommend a re-testing schedule based on your baseline result and any changes you make.
Is this testing available in every US state?
No, direct-to-consumer lab testing is restricted or prohibited in New York, New Jersey, and Rhode Island, so residents of those states may be blocked at the partner's checkout. If you live elsewhere in the US, you can typically order online and visit a nearby draw location.
References
- [1] Vitamin D - Health Professional Fact Sheet — NIH Office of Dietary Supplements
- [2] Evaluation, Treatment, and Prevention of Vitamin D Deficiency: An Endocrine Society Clinical Practice Guideline — Endocrine Society (Journal of Clinical Endocrinology & Metabolism)
- [3] Vitamin D - Health Professional Fact Sheet — NIH Office of Dietary Supplements
- [4] Iron-Deficiency Anemia — StatPearls, NCBI Bookshelf (NIH)
- [5] Limitations of Serum Ferritin in Diagnosing Iron Deficiency in Inflammatory Conditions — International Journal of Chronic Diseases
- [6] Diagnosis of Hemochromatosis — NIDDK (NIH)
- [7] Dose–response relationship of serum ferritin and dietary iron intake with metabolic syndrome and non-alcoholic fatty liver disease incidence: a systematic review and meta-analysis — Frontiers in Nutrition
Reviewed by
Jason August
Founder & Editorial Lead
Jason August is the founder of Metabolic Markers and its parent company, Advancing Development. He has spent his career building and scaling real-world ventures, including as a founding team member at Build-A-Bear Workshop during its growth from startup to global public company, and since then across capital, real estate, adaptive reuse, and hospitality. He founded Metabolic Markers to make blood-biomarker testing easier to understand and access, and oversees the site’s content and editorial accuracy. Jason is not a medical professional; all content on this site is educational, reviewed for accuracy, and never a substitute for advice from a licensed physician.
Other ways to think about this offer
Same testing, covered from a different starting point.
Related lab test panels
Comprehensive Wellness Blood Test Panel with Vitamin D
A full-body baseline in one blood draw: blood counts, metabolism, cholesterol, thyroid, iron, and vitamin D status.
View panelMicronutrient Blood Test Panels: Vitamins, Minerals & Antioxidants
Lab panels that quantify the vitamins, minerals, and antioxidants your body runs on, plus heavy-metal exposure.
View panelVitamin & Mineral Blood Tests: Check Your Micronutrient Levels
Nine tiered lab panels that measure the vitamins and minerals your body runs on, from a basic iron and magnesium screen to a full micronutrient workup.
View panel