How to read a vitamin D result
Quick answer: To read a vitamin D result, find the unit, check the category and ask about a dose.
- Find the unit. Results are in ng/mL or nmol/L; 1 ng/mL equals 2.5 nmol/L. The checker converts either.
- Check the category. Below 20 ng/mL (50 nmol/L) is deficient, 20–29 insufficient, and 30–100 sufficient.
- Ask about a dose. Treatment depends on how low the level is; your doctor will suggest a dose and when to retest.
Why vitamin D is often low
Your skin makes vitamin D from sunlight. Spending most of the day indoors, covering skin, darker skin, living far from the equator, older age and extra weight all make deficiency common, including in sunny countries.
Different guidelines
The Endocrine Society calls 30 ng/mL or more sufficient, which this checker uses. Some countries and labs treat 20 ng/mL (50 nmol/L) as enough for most people. Very high levels (over 100–150 ng/mL) usually come from high-dose supplements and can be harmful.
Important
This tool explains results in plain words; it can't diagnose anything. Your doctor reads them alongside your symptoms, history and medicines.
Frequently asked questions
Is vitamin D of 15 ng/mL low?
Yes, under 20 ng/mL is considered deficient. It's common and usually treated with supplements; ask your doctor for the right dose.
What is 50 nmol/L in ng/mL?
20 ng/mL. Divide nmol/L by 2.5 to get ng/mL.
Are my results uploaded or stored?
No. The report is read inside your browser, on your device. Nothing is sent to a server or saved after you close the page.