Riboflavin (Vitamin B2)

Riboflavin, also called vitamin B2, is a water-soluble vitamin that forms part of two important coenzymes: flavin mononucleotide, or FMN, and flavin adenine dinucleotide, or FAD. These molecules help enzymes carry out chemical reactions involved in energy production and normal cell function .¹

FMN and FAD participate in metabolism, including the processing of fats. They also connect riboflavin with other vitamins: FAD is needed to convert the amino acid tryptophan into niacin, while FMN is involved in producing the coenzyme form of vitamin B6 .¹

Most riboflavin in food is present as FMN or FAD rather than as free riboflavin. Absorption occurs mainly in the upper small intestine, and the body retains only small stores. Riboflavin also has a distinctive physical property: it is yellow and fluoresces under ultraviolet light. Exposure to ultraviolet or visible light can inactivate it and its derivatives .¹