Vitamin D
Also written: 25-OH vitamin D
What it measures
The level of stored vitamin D in the blood.
Why it is ordered
Considered in some bone-related situations or when risk factors are present. Not routinely needed for everyone.
How to prepare
Usually no fasting needed. Mention any supplement you are taking.
Units
ng/mL ↔ nmol/L (nhân 2,496) — convert here
What to ask
- Do I actually need this test
- If I supplement, when should it be rechecked
- Is repeat testing necessary
This page does not include reference ranges and does not say whether your number is high or low. Reference ranges differ between laboratories and between people — read yours on your own report, with your clinician.