What Is L Phenylalanine?

According to the University of Maryland Medical Center, L phenylalanine is an amino acid that occurs naturally, as opposed to D Phenylalanine, which is artificially made. L phenylalanine is a neurotransmitter that is thought to have marked medical benefits. However, there are also some risks and considerations associated with this amino acid.

Sources

Protein rich foods are the only source of L phenylalanine. Meat, beans, dairy products, poultry and fish are all good sources of L phenylalanine. People who eat these foods on a regular basis usually have sufficient L phenylalanine; however, vegans or people who severely limit their intake of protein may need to take D phenylalanine.

Vitiligo Treatment

According to the University of Maryland Medical Center, L phenylalanine is useful in the treatment of vitiligo. In this condition, L phenylalanine in a topical form is applied to the skin and used in conjunction with UVA radiation. L phenylalanine may also be effective as part of treatment plan for depression.

Phenylketonuria

Some people are born with a condition called phenylketonuria, which is an inability to properly digest phenylalanine. People affected by phenylketonuria shouldn't ingest L Phenylalanine, which means they must limit the amount of proteins and dairy products. Symptoms of this condition, according to the Mayo Clinic, usually manifest between three to six months of age and include an abnormally small head, eczema, hyperactivity and developmental delay. According to the Penn State Hershey Milton S. Hershey Medical Center, infants in the United States are tested after birth for this condition using a blood sample obtained through a heel stick.

Warnings

Pregnant women, children and people with kidney disease must be careful about the total amount of phenylalanine they ingest, including both varieties. It is also important to note that it is possible to overdose on L phenylalanine. Doses higher than 5,000 milligrams of the amino acid can cause marked nerve damage.

Drug Interactions

According to the University of Maryland Medical Center, people taking anti-psychotic drugs or Levodopa (a medication for Parkinson's disease) should avoid L phenylalanine in high doses, as this causes the Levodopa to absorb slower and less effectively than normal. Additionally, it reports that people taking Monoamine oxidase inhibitors (MAOIs), neuroleptic drugs and Baclofen should avoid therapeutic levels of L phenylalanine.