phenylketonurics

What Is A Source Of Phenylalanine? Phenylalanine occurs naturally in many protein-rich foods, such as milk, eggs and meat. Phenylalanine is also sold as a dietary supplement. What food is high in phenylalanine? Phenylalanine is found in most protein-containing foods such as milk, eggs, cheese, nuts, soybeans, chicken, beef, pork, beans and fish. What is