Animal proteins provide the richest sources of L-arginine. Seafood, such as tuna, salmon, shrimp and crab, contains high levels of the amino acid, while beef, pork, poultry and most dairy also provide a rich supply. Arginine-rich plant sources include legumes, grains, nuts and some greens.
People who regularly consume seafood generally receive a sufficient supply of L-arginine for dietary needs. Among fish, the sockeye salmon contains the highest level of the amino acid per gram, followed by tuna and haddock. Shellfish of almost every kind also rate highly for arginine levels.
Turkey, liver, beef, pork, chicken and turkey all rate highly for arginine levels. Eggs also contain significant levels. Dairy processed with fresh curds is also very high in arginine, so cottage cheese and ricotta have especially high levels among cheeses.
Among plant foods, legumes, such as cooked soybeans, garbanzo beans and lentils, all contain high levels of arginine, with soybeans ranking alongside seafood for arginine content. Grains, such as oats, wheat germ and buckwheat, also serve as good sources. Almost all nuts and seeds contain significant levels of the compound. Vegetables, such as spinach, seaweed, onions, garlic, leeks and peppers, provide the body with the substrates needed to produce arginine, allowing it to produce its own self-regulating supply. Vegetarians and vegans should be especially mindful of these sources of arginine.