Provided is a method for preparing β-alanine, the method comprising: preparing a β-alanine product from a reactant containing fumaric acid and aqueous ammonia in the presence of a catalyst, wherein the catalyst contains a catalyst composition containing aspartase and L-aspartic acid-α-decarboxylase, and adding fumaric acid during the reaction, wherein the total moles of the fumaric acid added is equal to the initial moles of the aqueous ammonia in the reactant minus the initial moles of the fumaric acid in the reactant. Also provided are methods for preparing a β-alanine salt (in particular calcium β-alanine, sodium β-alanine, and potassium β-alanine) and a pantothenate (in particular calcium pantothenate, sodium pantothenate, and potassium pantothenate).