What is this test?
This test measures the level or laboratory status of the specified vitamin. It can support an assessment of dietary intake, absorption, and supplement use.
Why might it be ordered?
- When symptoms or circumstances raise a clinical concern about deficiency or excess.
- To monitor a prescribed supplement or treatment.
- As part of a broader assessment of nutritional and general health.
What sample is needed?
These markers are usually measured in blood, but the exact specimen and method can differ. Confirm the required specimen with the laboratory.
How should you prepare?
Supplements can affect the measured level. Do not stop them on your own; state what you take and when, and ask whether fasting or a specific collection time is required.
How should you understand the result?
The value is compared with the laboratory reference interval. An abnormal value does not identify a cause or disease by itself and is interpreted with symptoms, diet, and treatment.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.