Vitamin A is a fat-soluble vitamin that promotes normal vision, contributes to growth of bone, teeth, and soft tissues, and helps maintain skin and mucous membranes. Vitamin A also supports the formation of thyroid hormones and helps to fight infections.
An 8 to 12 hour fast is required for this blood test. However, drink plenty of water and take your medications as prescribed. No foods or supplements containing vitamin A should be ingested in the previous 48 hours leading up to the test.
This test does not measure beta carotene, the precursor to vitamin A (the active form). If you would like to measure beta carotene use test code LC001529.