For those of us in USA, we use ng/ml, whereas the rest of the world uses nmol/l to measure Vitamin d25 blood levels. This makes it difficult to understand what researchers are using as cut-off points for "low" or "high" threshold values.
Here is the conversion formula:
- to convert nmol/L to
ng/mL, multiply nmol/L by 0.4;
- to convert ng/mL to nmol/L, multiply ng/mL by
2.5.]