The Flavin Adenine Dinucleotide (FAD B2) test is used to measure FAD levels in the body, an active form of Vitamin B2 (riboflavin) that plays a vital role in several metabolic processes. This compound is essential for the function of a range of enzymes involved in energy production and nutrient conversion. The test is typically conducted when there is suspicion of riboflavin deficiency or when evaluating metabolic disorders. This test helps doctors diagnose health conditions that may affect flavin levels and provides important information about the body's ability to utilize energy. It is always recommended to consult a doctor for an accurate interpretation of the results.