How do vitamins help chemical reactions take place in cells?

Vitamins facilitate essential chemical reactions in cells primarily by acting as coenzymes, which are non-protein components that assist enzymes in their catalytic functions.12

Most water-soluble vitamins function within enzyme systems to transfer specific groups, hydrogen ions, or electrons between molecules. This process is critical for metabolism, as it allows for the interconversion of fats, proteins, and carbohydrates and their subsequent transformation into metabolic energy. For example, coenzyme A—derived from pantothenic acid—acts at the hub of the tricarboxylic acid cycle to control energy release.12

While vitamins do not serve as energy sources themselves, they regulate the reactions that utilize macronutrients. Beyond their role as coenzymes, some vitamins assist in maintaining biological membranes or function at the genetic level to control the synthesis of specific enzymes. Other vitamins, such as vitamin C and vitamin E, act as antioxidants, protecting cells by neutralizing reactive molecules.23