Vitamin D Test Test
A vitamin D test measures the level of vitamin D in your blood to see if you have enough for healthy bones, muscles, nerves, and immune system.
What this test measures
A vitamin D test measures the level of 25-hydroxyvitamin D (25(OH)D) in your blood, which is the form your body uses. It shows whether your vitamin D levels are sufficient, insufficient, deficient, or toxic.
What your results mean
Reference ranges vary by laboratory and by your age and sex. MedlinePlus does not publish a single normal range for this test — always read your result against the range printed on your own lab report and discuss it with your provider.
Higher-than-normal results
If your total vitamin D levels are high or toxic, it usually means you're getting too much from supplements. This can cause serious damage to your organs and blood vessels.
Lower-than-normal results
If your total vitamin D levels are deficient or insufficient, it may mean you don't get enough from diet or sunlight, have trouble absorbing it, have kidney or liver disease, or take a medicine that affects vitamin D levels.
Frequently asked questions
What does a vitamin D test measure?
It measures the level of 25-hydroxyvitamin D (25(OH)D) in your blood, which is the most accurate way to see if you have enough vitamin D.
Why is vitamin D important?
Vitamin D helps your body absorb calcium to build healthy bones and teeth. It also helps keep your muscles, nerves, and immune system working normally.
How can I get vitamin D?
You can get vitamin D from sunlight, certain foods (like egg yolks, liver, and fatty fish), and supplements.
What do the test results mean?
Results are usually described as deficient, insufficient, sufficient, or toxic. Your provider can explain what your results mean for your health.
Should everyone get a vitamin D test?
No, routine vitamin D testing is not recommended for everyone. Your provider can tell you if a test is right for you.
Related lab tests
Sources
- MedlinePlus: Vitamin D Test — NIH MedlinePlus
Last updated . Information is aggregated from official public sources and is not a substitute for professional medical care.