Aspartic acid is a non-essential amino acid. In plants and microorganisms, aspartic acid is the precursor to several amino acids, including four that are essential: methionine, threonine, isoleucine, and lysine.
Aspartic acid is found in both animal sources (luncheon meats, sausage meat, wild game) and
vegetable sources (sprouting seeds, oat flakes, avocado, asparagus).