Vitamin A testing is a medical procedure used to measure the levels of vitamin A in a person’s blood. This test is typically ordered by a healthcare provider to diagnose and monitor vitamin A deficiency or toxicity. Vitamin A is essential for maintaining healthy vision, immune system function, and skin health. However, excessive amounts of vitamin A can be toxic, leading to a range of symptoms such as nausea, fatigue, and skin irritations. The test can be performed through a blood sample, and the results are usually available within a few days. Based on the results, a healthcare provider may recommend changes to a person’s diet or the use of vitamin A supplements to correct deficiencies or manage toxicity.