Vitamin A Serum (8 hour fast required)
- A, Vitamin
- Retinol, Serum
The Vitamin A Serum blood test is used in the differential diagnosis of hypervitaminosis A. A combination of a low serum carotene level and a low vitamin A suggests inadequate vitamin A nutrition.
Patients must fast a minimum of eight hours. No foods containing vitamin A should be ingested in the previous 48 hours by patients older than six months. For those who are younger than six months, the period is 24 hours.