How to Convert Vitamin D ng/mL to nmol/L
Vitamin D status is measured as 25-hydroxyvitamin D (25-OH vitamin D). US labs usually report it in ng/mL, while most other countries use nmol/L. The two units describe the same level, so converting lets you compare results and reference ranges across reports.
The conversion factor is 2.496, derived from the molecular weight of 25-hydroxyvitamin D — the same molecular-weight method the nmol/L to ng/mL converter uses for other hormones and vitamins:
Vitamin D nmol/L = Vitamin D ng/mL × 2.496 Vitamin D ng/mL = Vitamin D nmol/L ÷ 2.496 Vitamin D ng/mL to nmol/L Chart
Use this chart to compare common vitamin D values and the status band each one usually falls into. Interpretation thresholds vary by guideline and lab, so always compare with the reference range on your own report.
| ng/mL | nmol/L | Typical status |
|---|---|---|
| 10 ng/mL | 25.0 nmol/L | Deficient |
| 20 ng/mL | 49.9 nmol/L | Insufficient (lower limit) |
| 30 ng/mL | 74.9 nmol/L | Sufficient (common target) |
| 40 ng/mL | 99.8 nmol/L | Optimal range |
| 50 ng/mL | 124.8 nmol/L | Upper optimal |
| 60 ng/mL | 149.8 nmol/L | High-normal |
| 80 ng/mL | 199.7 nmol/L | High |
| 100 ng/mL | 249.6 nmol/L | Possible excess |
nmol/L to ng/mL Reverse Chart
If your report uses nmol/L, this reverse chart helps you compare the value with ng/mL reference ranges.
| nmol/L | ng/mL |
|---|---|
| 25 nmol/L | 10.0 ng/mL |
| 50 nmol/L | 20.0 ng/mL |
| 75 nmol/L | 30.0 ng/mL |
| 100 nmol/L | 40.1 ng/mL |
| 125 nmol/L | 50.1 ng/mL |
| 150 nmol/L | 60.1 ng/mL |
| 200 nmol/L | 80.1 ng/mL |
| 250 nmol/L | 100.2 ng/mL |
Vitamin D Status Ranges
Many references describe vitamin D status using these approximate bands. They are general educational ranges, not a diagnosis:
- Deficient: below 50 nmol/L (below 20 ng/mL).
- Insufficient: 50–75 nmol/L (20–30 ng/mL).
- Sufficient: 75 nmol/L (30 ng/mL) and above.
- High / possible excess: above 250 nmol/L (above 100 ng/mL).
Targets differ between guidelines, and the right level depends on age, pregnancy, bone health, and other factors. Use your lab's reference range and your provider's advice for interpretation.
Because vitamin D regulates calcium absorption, it is often reviewed alongside a serum calcium result. You can convert calcium between mg/dL, mmol/L, and mEq/L with the calcium conversion calculator.
Worked Example
Suppose your vitamin D result is 25 ng/mL and you want nmol/L. Multiply by 2.496:
25 × 2.496 = 62.4 nmol/L 62.4 nmol/L sits in the insufficiency band in many guidelines. For the reverse direction, a level of 100 nmol/L is about 40 ng/mL.
Frequently Asked Questions
How do you convert vitamin D ng/mL to nmol/L?
Multiply the ng/mL value by 2.496. For example, 30 ng/mL equals about 74.9 nmol/L.
How do you convert vitamin D nmol/L to ng/mL?
Divide the nmol/L value by 2.496. For example, 75 nmol/L is about 30 ng/mL.
What is 30 ng/mL vitamin D in nmol/L?
30 ng/mL equals about 75 nmol/L, a level many guidelines use as the sufficiency threshold.
What vitamin D level is deficient?
Many references consider below 50 nmol/L (20 ng/mL) deficient, with 50–75 nmol/L (20–30 ng/mL) insufficient. Thresholds vary by guideline.
Is this the same as 1,25-dihydroxyvitamin D?
No. Vitamin D status testing uses 25-hydroxyvitamin D. The active form, 1,25-dihydroxyvitamin D, is reported in pmol/L or pg/mL and uses a different conversion — see the pmol/L to pg/mL calculator for that.
Conclusion
Converting vitamin D between ng/mL and nmol/L is a simple multiply or divide by 2.496. Use this calculator to compare results across labs and reference ranges, then rely on your healthcare provider to interpret what your vitamin D level means for you.