The Vitamin B3 (Niacin) by HPLC test is a laboratory procedure used to measure the levels of niacin in the blood. Vitamin B3 is an essential nutrient that plays a key role in energy metabolism, skin health, and the proper functioning of the nervous system. A blood sample is collected and sent to a laboratory, where it is analyzed using High-Performance Liquid Chromatography (HPLC). This technique ensures highly accurate and precise measurement of niacin levels in the blood. This test is recommended in cases of suspected vitamin deficiency or when symptoms such as fatigue, irritability, or skin issues are present. The results help doctors assess the patient's nutritional status and determine whether supplementation or dietary adjustments are necessary to maintain healthy levels of Vitamin B3, supporting overall well-being and proper bodily function.