Phenylalanine (Urine)

High levels of phenylalanine may be due to excessive protein intake or a metabolic block in the conversion of phenylalanine to tyrosine. Iron, vitamin C, and niacin are necessary for this enzymatic step. Check tyrosine level and, if low, supplement tyrosine and iron.

In rare cases, high phenylalanine build up in the body can also be due to an inherited disorder called Phenylketonuria. It is caused by a defect in the gene that helps create the enzyme needed to break down phenylalanine.

Phenylalanine is required for the synthesis of proteins and is the precursor of tyrosine. Tyrosine is required for the production of neurotransmitters (eg.dopamine, DOPA, epinephrine) and, thyroid hormone. Phenylalanine is typically low as a result of unbalanced protein in the diet or gastrointestinal dysfunction, particularly hypochlorhydria. Phenylalanine is often low in patients with endogenous depression. Soy protein, legumes/lentils, cheese, nuts and shellfish are good dietary sources of phenylalanine.

Phenylalanine is a precursor for the amino acid tyrosine, which is essential for making neurotransmitters (e.g. epinephrine, norepinephrine, dopamine) and thyroid hormone. Neurotransmitters are the chemicals that communicate between nerve cells in the brain. It can relieve pain, alleviate depression, and suppress the appetite. Low levels may indicate a stressful lifestyle, leading to memory loss, fatigue, and depression.