A vitamin profile test detects the levels of most major vitamins in a patient's bloodstream and is a useful tool to screen for malnutrition caused by a poor diet or digestive illness. Different tests measure different levels of vitamins in the blood, but most will screen for deficiencies or overdoses of vitamins A, C, E, B1, B6 and B12, as well as beta carotene, folate and vitamin D 25-hydroxy. This kind of test covers the most significant vitamins in the human diet, including those that could result in serious problems if deficiencies are allowed to persist long-term.

Because many of the vitamins that are measured by a vitamin profile blood test can be influenced easily by a patient's diet, it's important to fast for about 12 hours before having any blood drawn. This fast should include no food and no beverages other than water. Many patients choose to have their vitamin profile test performed early in the morning, before breakfast, to ensure a more comfortable fast and truly accurate test results.

If a vitamin profile test returns results that show low levels of any of the vitamins it measures, patients can correct the problem through proper supplementation. It is important not to take folate alone if the test shows low levels of B vitamins, however, as the folate supplements can prevent later tests from showing a deficiency in B6 or B12. Other corrective options include a diet that includes a greater variety of fresh, unprocessed foods and more exposure to direct sunlight.

These tests require FASTING for approximately 10 hours to obtain accurate results.