There is no single agreed normal for a vitamin D test. This page sets the Endocrine Society, Institute of Medicine and WHO regional lines side by side in ng/mL and nmol/L, with fasting, repeat testing, Egypt and the questions to ask your doctor.
There is no single agreed normal level for a vitamin D blood test. The Endocrine Society’s 2011 guideline called a blood 25(OH)D below 20 ng/mL (50 nmol/L) deficiency, but its 2024 guideline no longer endorses fixed levels, and a 2024 WHO regional report says no cut-off is globally agreed. The range printed on your report, and your doctor, govern.
This page sets out where named sources put their lines, in both units, and what to ask. It does not read your result, tell you it is normal or low, or diagnose anything. The Endocrine Society (2024) says the 25(OH)D concentration most accurately reflects vitamin D status, and MedlinePlus (updated 4 December 2024) says most vitamin D blood tests measure it.
In short:
- Sources differ: the Endocrine Society’s 2011 guideline put deficiency below 20 ng/mL (50 nmol/L) and called 21 to 29 ng/mL insufficiency, it dropped fixed levels in 2024, and the Gulf consensus also puts deficiency below 50 nmol/L but calls above 50 nmol/L sufficient for the general population.
- ng/mL times 2.5 gives nmol/L: check the unit beside your number.
- No special preparation is needed (MedlinePlus, 4 December 2024). Routine testing is not recommended for everyone, and no source we read gives one repeat interval: your doctor decides.
Last checked: 1 November 2026, on the pages listed under Sources. Guidelines and pages change, so confirm with your doctor.
What is the normal range for a vitamin D test?
| Source | ng/mL | nmol/L | What the source says |
|---|---|---|---|
| Endocrine Society guideline, 2011 | Below 20 | Below 50 | Defines deficiency |
| Endocrine Society guideline, 2011 | 21 to 29 | 52.5 to 72.5 (derived) | Defines insufficiency |
| Institute of Medicine (IOM) committee, 2011 | 16 | 40 | Covers the requirements of about half the population |
| IOM committee, 2011 | 20 | 50 | Covers the requirements of at least 97.5% of the population |
| IOM committee, 2011 | Above 50 | Above 125 | Should raise concern among clinicians about potential adverse effects |
| Gulf Cooperation Council consensus, 2020, as reported by WHO (2024) | Below 20 (derived) | Below 50 | Deficiency. Above 50 nmol/L is sufficiency for the general population; above 75 nmol/L (30 ng/mL, derived) is the target for frail, osteoporotic and older people |
| Endocrine Society guideline, 2024 | None | None | No longer endorses specific levels to define sufficiency, insufficiency and deficiency |
Cells marked “derived” apply the 2.5 factor to a pair the source prints; they are not published figures. The IOM row comes from the committee’s own summary (Ross et al., 2011). The Endocrine Society’s 2024 guideline replaces its 2011 one (last row). The range printed on your report, and your doctor, govern.
The IOM values describe the healthy population, not cut-offs for people with specific diseases (Ross et al., 2011), and the Endocrine Society’s 2024 guideline covers only people without established indications for testing or treatment. The WHO regional report (2024) says non-standardised laboratory methods complicate interpretation. Which line applies to you is your doctor’s call.
ng/mL or nmol/L: which unit is on my report?
The papers print both units side by side: the Endocrine Society (2011) writes 20 ng/mL as 50 nmol/L, and the IOM committee (2011) pairs 16 with 40, 20 with 50, 30 with 75 and 50 with 125. That is 2.5 nmol/L for each 1 ng/mL. A nmol/L number read against an ng/mL line, or the reverse, lands in the wrong place, so check the unit beside your number. The same trap exists for HbA1c: HbA1c: the normal range, the units (% and mmol/mol) and what to ask your doctor sets it out.
| If the report says | The same level in the other unit | Where the pair comes from |
|---|---|---|
| 16 ng/mL | 40 nmol/L | IOM committee, 2011 |
| 20 ng/mL | 50 nmol/L | Endocrine Society 2011; IOM committee 2011 |
| 30 ng/mL | 75 nmol/L | IOM committee 2011; Endocrine Society 2024 |
| 50 ng/mL | 125 nmol/L | IOM committee, 2011 |
| 5 ng/mL | 12.5 nmol/L (derived) | Worked with the 2.5 factor |
My vitamin D is 5: what does that number mean?
A report that says 5 is unclear until you read the unit: 5 ng/mL is 12.5 nmol/L, and 5 nmol/L is 2 ng/mL (both derived with the 2.5 factor). Either way it sits below the lowest figure in the first table. That places a number in published tables; it is not a reading of your result, and this page cannot say how much it matters. Your doctor decides what it means for you and what comes next, so take the report with you.
Does a vitamin D test need fasting?
No special preparation is needed for a vitamin D test, says MedlinePlus (updated 4 December 2024). It adds that you should tell your provider about all the medicines, vitamins and supplements you take, because they may affect results, and should not stop any medicine unless your provider says so. Your lab’s own instructions govern. Other tests do need a fast: Which blood tests need fasting? The table, and what to ask the lab sets them side by side.
Does everyone need a vitamin D test?
- MedlinePlus (updated 4 December 2024): routine vitamin D testing is not recommended for everyone.
- Endocrine Society (June 2024): suggests against routine 25(OH)D testing in all the populations it considered, including during pregnancy and in adults with dark complexion or obesity; it does not apply to conditions that substantially alter vitamin D physiology, such as malabsorption.
- WHO regional report (2024), recommendations to Member States: test only people who have symptoms or are at risk of vitamin D deficiency, in line with current guidelines, with no population-wide screening using 25(OH)D.
Whether you have an established reason for the test is your doctor’s decision.
When should a vitamin D test be repeated?
No source we read gives one repeat interval for everyone. The Endocrine Society’s 2024 guideline suggests against routine follow-up 25(OH)D testing to guide vitamin D dosing in generally healthy adults and during pregnancy, and says testing to monitor response to therapy may be required in special populations, such as people with malabsorption. The WHO regional report (2024) mentions Kuwait Osteoporosis Society recommendations on how often at-risk people should be tested, without printing them. Whether and when to repeat is your doctor’s decision, so ask both questions.
What should I ask my doctor about my vitamin D test?
- Is my result in ng/mL or nmol/L, and what range and method does this lab use?
- Why was this test ordered for me, and does anything in my health history change how to read it?
- Does it need repeating, and when?
- Do any medicines, vitamins or supplements I take affect the result?
- What is the next step, and who decides it?
Pick the questions that matter to you and take the list with you:
Try it
Your questions for the doctor
Tick the questions you want to ask, add your own, then copy, print or send the list to yourself.
4 questions on your list.
What you type stays on this page. Nothing is saved or sent unless you copy, print or send it yourself.
In Egypt: which range applies to my report?
A Ministry of Health and Population statement of 7 May 2026, carried on the State Information Service page (updated 9 May 2026), says Egypt’s presidential initiative for early detection of chronic disease covers blood pressure, random and cumulative blood sugar, blood fats, kidney function and body mass index. Vitamin D is not among the tests the page names (read 1 November 2026).
One Ministry page does print vitamin D levels: a Ministry of Health and Population news page dated 19 September 2017, on nutrition for people with epilepsy, whose closing section on vitamin D gives blood 25(OH)D bands of below 20 ng/mL, 20 to 30 ng/mL and above 30 ng/mL, the last called sufficient (read 1 November 2026). It is an old news item, not a clinical guideline: its vitamin D section speaks of American adults, names no author or source, and prints no nmol/L figures. Web searches limited to the Ministry, Egyptian Drug Authority and State Information Service sites on 31 October and 1 November 2026 found no other page printing vitamin D ranges or testing guidance, which does not prove none exists.
The WHO Regional Office for the Eastern Mediterranean, based in Cairo, says in its 2024 report that there is an urgent need for evidence-based guidance on vitamin D deficiency in the region. Ask your lab which range and unit it prints, and your doctor which applies.
Where Medigize stands
Medigize is a navigation tool. It does not run lab tests or read your result. We are building a record that moves with the patient, shared only with their consent. If you would like to follow that work, you can register your interest.
Frequently asked questions
What is the normal range for vitamin D?
No single range is agreed. The Endocrine Society (2011) defined deficiency as below 20 ng/mL (50 nmol/L), its 2024 guideline no longer endorses specific levels, and the Gulf consensus, as reported by WHO (2024), also puts deficiency below 50 nmol/L. The range printed on your report, and your doctor, govern.
Is 20 ng/mL the same as 50 nmol/L?
Yes. The Endocrine Society (2011) and the IOM committee (2011) both print the pair, which is 2.5 nmol/L for each 1 ng/mL.
Does a vitamin D test need fasting?
No special preparation is needed, says MedlinePlus (updated 4 December 2024). Your lab’s own instructions govern.
How often should I repeat a vitamin D test?
No source we read gives one interval for everyone. Your doctor decides.
Medigize is a non-diagnostic navigation tool. This is general information, not medical advice. In an emergency, call an ambulance or go to the nearest emergency department.
Sources
- Demay MB et al.: Vitamin D for the Prevention of Disease: An Endocrine Society Clinical Practice Guideline, J Clin Endocrinol Metab 2024;109(8):1907–1947 (doi 10.1210/clinem/dgae290), published 3 June 2024 (a correction appeared in 2025;110(3):e916), read 1 November 2026
- Holick MF et al.: Evaluation, Treatment, and Prevention of Vitamin D Deficiency: an Endocrine Society Clinical Practice Guideline, J Clin Endocrinol Metab 2011;96(7):1911–1930 (doi 10.1210/jc.2011-0385), read 1 November 2026
- Ross AC et al.: The 2011 Report on Dietary Reference Intakes for Calcium and Vitamin D from the Institute of Medicine: What Clinicians Need to Know, J Clin Endocrinol Metab 2011;96(1):53–58 (doi 10.1210/jc.2010-2704), published online 30 November 2010, read 1 November 2026
- WHO Regional Office for the Eastern Mediterranean: Summary report on the consultation on the development of regional guidelines on vitamin D supplementation for the WHO Eastern Mediterranean Region (Beirut, 15–16 May 2023), WHO-EM/NUT/313/E, Cairo 2024, read 1 November 2026
- MedlinePlus (US National Library of Medicine): Vitamin D Test, updated 4 December 2024, read 1 November 2026
- Egypt’s State Information Service (SIS): early detection of kidney disease and chronic-disease screening initiative, carrying a Ministry of Health and Population statement of 7 May 2026, page updated 9 May 2026, read 1 November 2026
- Egypt’s Ministry of Health and Population: news page on nutrition for people with epilepsy, with a closing section on vitamin D, dated 19 September 2017, read 1 November 2026
Last updated:
Explore Medigize
Medigize is in development. Explore our current scope and express your interest.