Vitamin D Test
Reviewed
A vitamin D test measures the level of 25-hydroxyvitamin D (25(OH)D) in your blood to check if you have enough vitamin D for healthy bones, teeth, muscles, nerves, and immune system. It is used when your provider suspects a bone or other health condition related to very low vitamin D levels, or if you have risk factors for deficiency. Routine testing is not recommended for everyone.
Preparation and collection
You don't need any special preparations. Tell your provider about all medicines, vitamins, and supplements you take, because they may affect your results. Do not stop taking any medicines unless your provider tells you to.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
- Routine vitamin D testing is not recommended for everyone.
What to do next
To learn what your vitamin D test results mean, talk with your provider.