L-valine is one of the branched chain amino acids (BCAA), which cannot be synthesized by the animal itself and must be absorbed from the diet to meet its nutritional needs. Therefore, L-valine is an essential amino acid. Amino acids are the basic structural units of protein synthesis, the precursor of other amines needed for metabolism, and are indispensable substances for life. At present, there are 20 to 30 kinds of known amino acids, some of which can be synthesized in the human body and are called non-essential amino acids, while others can not be synthesized in the human body and must be supplemented from the outside, and are called essential amino acids. Mammalian cells need 12 kinds of essential amino acids: L-arginine, L-cystine, L-histidine, L-leucine, L-isoleucine, L-lysine, L-methionine, L-phenylalanine Chemicalbook, L-threonine, L-tryptophan, L-tyrosine, L-valine. All of these amino acids are left-handed isomers, while some non-essential amino acids are right-handed isomer