Flavin mononucleotide (FMN) is a vital coenzyme derived from riboflavin (vitamin B2). It plays a crucial role in various biological processes, particularly in the electron transport chain, where it helps in the production of adenosine triphosphate (ATP), the energy currency of cells. FMN acts as a prosthetic group for several enzymes, facilitating redox reactions. In addition to its role in energy metabolism, FMN is involved in the metabolism of fats, carbohydrates, and proteins. It also contributes to the synthesis of flavin adenine dinucleotide (FAD), another important coenzyme. Deficiencies in FMN can lead to various health issues, highlighting its importance in nutrition.