Phenylalanine

The Basics

Phenylalanine is an essential amino acid. Inside the body, phenylalanine is converted into tyrosine, another amino acid. Tyrosine is then used to produce dopamine and norepinephrine, both neurotransmitters. All of these elements are important because of their relationship to the central nervous system.

Phenylalanine is used to treated depression (elevates mood), rheumatoid arthritis and osteoarthritis (decreases pain/inflammation), menstrual cramps, Parkinson's disease (improves speech and rigidity), Vitiligo (a skin pigment disorder), and cancer (melanoma, tumor growth).

Some people are born with phenylketonuria (PKU), a serious disorder found in some infants that requires treatment prior to the third month. If undetected or untreated, severe mental retardation results. In the United States, newborns are tested within 48 hours following their birth. People with this disorder must eat a phenylalanine-restricted diet supplemented with tyrosine. However, some PKU experts do not agree if this restricted diet is a life-long requirement for optimal health.

In children and adults, a phenylalanine deficiency may present any of the following symptoms: depression, memory problems, inability to be alert, bloodshot eyes, cataracts, increased appetite, decreased sexual interest, and decreased pigmentation of the skin.

Sources

Phenylalanine can be found in the following foods: soybean protein, frozen tofu, dried and salted cod, shellfish, lean meat, organ meat, skin-free chicken, cheese, milk, eggs, many seeds (watermelon, fenugreek, roasted soybean nuts), and chocolate.

As a supplement, phenylalanine is available in three forms: L-phenylalanine (most common), D-phenylalanine (painkilling properties), and DL-phenylalanine (combination).

Guidelines and Cautions

Phenylalanine supplements can be taken 30 minutes before a meal.
The recommended dietary allowances include:

For individual dosing guidelines, consult with a medical professional, especially if medication is taken on a regular basis.

Phenylalanine supplements should not be taken by pregnant or lactating women, diabetics, or persons with high blood pressure, PKU (phenylketonuria), pigmented melanoma (a skin cancer), or those who suffer from anxiety attacks.