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Optimal range: 7 - 92 micromol/g creatinine
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 5 - 20 mmol/mol creatinine
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 2 - 10 mmol/mol creatinine
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 7.4 - 69.6 nmol/mg Creatinine
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 40 - 74 umol/L
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 5 - 239 umol/g Cr
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy.
Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 6.07 - 17.46 qmol/dL
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 30 - 130 qmol/24 hours
LEARN MOREOptimal range: 51.2 - 121 umol/L
Phenylalanine is an essential amino acid found in most foods which contain protein such as meat, fish, lentils, vegetables, and dairy. Phenylalanine is the precursor to another amino acid, tyrosine. Because tyrosine is needed to form several neurotransmitters (dopamine, epinephrine, and norepinephrine), as well as thyroid hormone and melanin, phenylalanine intake is important.
Optimal range: 31 - 100 µmol/g Crea
Phenylalanine is an essential aromatic amino acid that serves as the biochemical starting point for several critical compounds in the body, including the catecholamine neurotransmitters — dopamine, noradrenaline, and adrenaline. On the Neurotransmitter XL panel, phenylalanine provides valuable insight into neurotransmitter synthesis capacity, stress metabolism, and amino acid balance.
Because the body cannot produce phenylalanine, it must be obtained from dietary protein sources such as meat, eggs, fish, dairy, soy, and legumes. Once absorbed, phenylalanine is converted into tyrosine via the enzyme phenylalanine hydroxylase (PAH), a process dependent on the essential cofactor tetrahydrobiopterin (BH4), as well as iron and vitamin B6. Tyrosine then serves as the substrate for dopamine synthesis, which can subsequently be converted into noradrenaline and adrenaline.
Thus, phenylalanine is the first building block in the catecholamine biosynthetic chain, influencing motivation, alertness, focus, stress resilience, and energy.
Optimal range: 31.7 - 71 nmol/ML
Final products include: DOPA, dopamine, norepinephrine, epinephrine, thyroid hormones, melanin, in TCA cycle, or 4-hydroxyphenylacetic acid.
Optimal range: 42 - 95 µmol/L , 4.2 - 9.5 µmol/dL
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.
Optimal range: 8 - 71 micromol/g creatinine
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.
Optimal range: 0 - 2.01 Ratio
The Phenylalanine/Tyrosine Ratio evaluates the body’s ability to convert phenylalanine to tyrosine; Conversion enzyme requires tetrahydrobiopterin (BH4), niacin (B3), and iron as cofactors.
Optimal range: 0.53 - 1.46 Ratio
The Phenylalanine/Tyrosine Ratio evaluates the body’s ability to convert phenylalanine to tyrosine; Conversion enzyme requires tetrahydrobiopterin (BH4), niacin (B3), and iron as cofactors.
Optimal range: 0 - 1.19 Ratio
The Phenylalanine/Tyrosine Ratio evaluates the body’s ability to convert phenylalanine to tyrosine; Conversion enzyme requires tetrahydrobiopterin (BH4), niacin (B3), and iron as cofactors.
Optimal range: 3.6 - 38.8 ug/gCR
LEARN MOREOptimal range: 0 - 0.3 ug/mg creatinine
Phenylglyoxylate is a Styrene metabolite.
Sources of exposure:
- Raw materials (benzene and ethylene) for the manufacture of styrene are supplied primarily from the petroleum industry.
- Used in the manufacture of synthetic rubbers, synthetic latex, polyesters, and plastic products.
- Automotive emissions, tobacco smoke, released from building materials, carpet backing. Low-level exposure may occure through ingestion of food products packaged in polystyrene containers.
- Packaging materials, toys, hobbies, crafts, house wares and appliances, electrical and thermal insulation, fiberglass, pipes, automobile parts, foam cups.
Optimal range: 0 - 105.6 mcg/g
Styrene is used in the manufacturing of plastics, in building materials, and is found in car exhaust fumes. Polystyrene and its copolymers are widely used as food-packaging materials. The ability of styrene monomer to leach from polystyrene packaging to food has been reported. Occupational exposure due to inhalation of large amounts of styrene adversely impacts the central nervous system, causes concentration problems, muscle weakness, fatigue, and nausea, and irritates the mucous membranes of the eyes, nose, and throat.
Reduce exposure by eliminating plastic and styrofoam containers for cooking, reheating, eating or drinking (especially warm or hot) food or beverages. Replace these containers with glass, paper, or stainless steel whenever possible. Elimination of styrene can be accelerated by sauna treatment, reduced glutathione supplementation (oral, intravenous, transdermal, precursors such as N-acetyl cysteine [NAC]).
Optimal range: 0 - 5 µg/g creatinine
Styrene is used in the manufacturing of plastics, in building materials, and is found in car exhaust fumes. Polystyrene and its copolymers are widely used as food-packaging materials. The ability of styrene monomer to leach from polystyrene packaging to food has been reported. Occupational exposure due to inhalation of large amounts of styrene adversely impacts the central nervous system, causes concentration problems, muscle weakness, fatigue, and nausea, and irritates the mucous membranes of the eyes, nose, and throat.