Biomarker ng/ml (nmol/l)
25-OH Vitamin D
Vitamin D storage form reflecting supply status
Also known as
calcidiol 25-hydroxy vitamin D 25(OH)D vitamin D3 storage calcifediol
Definition
25-Hydroxy vitamin D (calcidiol) is the primary storage form of vitamin D in the blood and the most reliable marker of individual vitamin D status. It is produced in the liver and converted to the active form calcitriol in the kidneys as needed. Optimal levels are essential for bone health, immune function, and hormonal balance.
| Parameter | Value |
|---|---|
| Unit | ng/ml (nmol/l) |
| Reference Range | 30–100 ng/ml (per laboratory standard) |
| Optimal Range (lab2go) | > 60 ng/ml (lab2go Optimum Zone for immune function and well-being) |
Last Reviewed: 17 April 2026 · maritta