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Optimal range: 0 - 7.1 mmol/mol creatinine
Kynurenic acid and Quinolinic acid are tryptophan metabolites formed through the kynurenine pathway. Tryptophan is the amino acid precursor to serotonin; its major route for catabolism is the kynurenine pathway. Important products of the kynurenine pathway include xanthurenic acid and kynurenic acid, which can further metabolize into quinolinic acid. The historical importance of this pathway has mainly been as a source of the coenzyme NAD+, which is important for all redox reactions in the mitochondria.
However, it is now understood that kynurenic and quinolinic acid have physiologic implications. This alternate pathway is upregulated in response to inflammation and stress, which can lead to deficient serotonin production. Kynurenic acid has shown some neuroprotective properties in the brain, since it can stimulate NMDA receptors. However, its importance on the periphery is still not fully elucidated. Some studies outline antiinflammatory, analgesic, antiatherogenic, antioxidative, and hepatoprotective properties to peripheral kynurenic acid.
The correlation to levels of urinary excretion needs further study. Quinolinic acid, in and of itself, can be inflammatory and neurotoxic.
Optimal range: 7.8 - 54 nmol/mg Creatinine
Kynurenic Acid is product of the metabolism of L-Tryptophan and appears in urine in Vitamin B6 deficiencies. Your body needs vitamin B6 (pyridoxine) to utilize amino acids derived from dietary protein.
Optimal range: 639 - 1200 µg/g creatinine
Kynurenic acid, a neuroactive metabolite produced from kynurenine, is regarded to be neuroprotective unless in excess amounts.
Optimal range: 0 - 1.5 ug/mgCR
Kynurenic Acid is product of the metabolism of L-Tryptophan and appears in urine in Vitamin B6 deficiencies. Your body needs vitamin B6 (pyridoxine) to utilize amino acids derived from dietary protein.
Optimal range: 0 - 7.1 mmol/mol creatinine
Kynurenic Acid is product of the metabolism of L-Tryptophan and appears in urine in Vitamin B6 deficiencies. Your body needs vitamin B6 (pyridoxine) to utilize amino acids derived from dietary protein.
Optimal range: 0 - 1.51 ug/mgCR
Kynurenic acid and Quinolinic acid are tryptophan metabolites formed through the kynurenine pathway. Tryptophan is the amino acid precursor to serotonin; its major route for catabolism is the kynurenine pathway. Important products of the kynurenine pathway include xanthurenic acid and kynurenic acid, which can further metabolize into quinolinic acid. The historical importance of this pathway has mainly been as a source of the coenzyme NAD+, which is important for all redox reactions in the mitochondria.
However, it is now understood that kynurenic and quinolinic acid have physiologic implications. This alternate pathway is upregulated in response to inflammation and stress, which can lead to deficient serotonin production. Kynurenic acid has shown some neuroprotective properties in the brain, since it can stimulate NMDA receptors. However, its importance on the periphery is still not fully elucidated. Some studies outline antiinflammatory, analgesic, antiatherogenic, antioxidative, and hepatoprotective properties to peripheral kynurenic acid.
The correlation to levels of urinary excretion needs further study. Quinolinic acid, in and of itself, can be inflammatory and neurotoxic.
Optimal range: 1 - 2.7 µmol/g Crea
Kynurenine is a central metabolite in the tryptophan degradation pathway, known as the kynurenine pathway, which plays a vital role in neurotransmitter balance, immune regulation, mitochondrial energy production, and oxidative stress control. It sits at a critical metabolic crossroads—linking the amino acid tryptophan with the synthesis of nicotinamide adenine dinucleotide (NAD+), a molecule essential for cellular energy and redox balance.
On the Neurotransmitter XL panel, kynurenine helps reveal whether tryptophan is being converted primarily into serotonin and melatonin (supporting mood and sleep) or diverted into stress- and inflammation-related pathways that generate neuroactive metabolites like quinolinic acid and kynurenic acid. Imbalances in kynurenine metabolism are often associated with chronic stress, immune activation, depression, fatigue, and mitochondrial dysfunction.
Optimal range: 0 - 11.6 nmol/mg Creatinine
Kynurenine is the primary breakdown product of tryptophan.
- Kynurenine blood levels have been found higher in type 2 diabetes, obesity, CVD, ADHD in children, HOMA-IR.
- Higher kynurenine increases Treg cell differentiation via the AhR (aryl hydrocarbon receptor) pathway.
- Blood levels were lower in acute ischemic stroke patients, older age, adults with ADHD.
- Upregulation of other tryptophan breakdown enzymes KMO (Kynurenine monooxygenase) and KYNU (Kynureninase) may decrease kynurenine.
Optimal range: 257 - 960 µg/g creatinine
Kynurenine is a central metabolite of the amino acid tryptophan with vasodilatory properties.
Optimal range: 0 - 4.4 nmol/ML
Kynurenine is the primary breakdown product of tryptophan.
- Kynurenine blood levels have been found higher in type 2 diabetes, obesity, CVD, ADHD in children, HOMA-IR.
- Higher kynurenine increases Treg cell differentiation via the AhR (aryl hydrocarbon receptor) pathway.
- Blood levels were lower in acute ischemic stroke patients, older age, adults with ADHD.
- Upregulation of other tryptophan breakdown enzymes KMO (Kynurenine monooxygenase) and KYNU (Kynureninase) may decrease kynurenine.
Optimal range: 0.6 - 16.4 mcg/mg creatinine
L-Lactate is a product of muscle use, so it is constantly produced in normal daily activity.
Optimal range: 3.22 - 10.49 %
The LA (Linoleic Acid) test within red blood cells (RBC) offers an in-depth analysis of linoleic acid levels, a crucial omega-6 fatty acid. As a primary component of cell membranes, LA plays a significant role in maintaining skin health, supporting the immune system, and promoting overall cellular function. The RBC measurement of LA provides a more accurate reflection of the body's cellular health and fatty acid balance over time compared to serum tests. This is particularly important for assessing inflammatory conditions, skin disorders, and cardiovascular health.
Optimal range: 11 - 46 Ratio
LA/DGLA is a fatty acid ratio.
LA/DGLA stands for linolenic acid (=LA) and dihomogammalinolenic acid (=DGLA).
The LA/DGLA ratio is a biomarker that can indicate functional zinc deficiency.
Optimal range: 6 - 12.3 Ratio
LA/DGLA is a fatty acid ratio.
LA/DGLA stands for linolenic acid (=LA) and dihomogammalinolenic acid (=DGLA).
The LA/DGLA ratio is a biomarker that can indicate functional zinc deficiency.
Reference range: -3, -2, -1, 0, +1, +2, +3
The Lachnospiraceae family is a diverse group of butyric acid producers, which have been associated with beneficial microbial and epithelial cell growth. Consumption of a Mediterranean diet decreased levels of species belonging to Lachnospiraceae.
Lachnospiraceae are known to increase with intake of cruciferous vegetables and wheat bran, and decrease with a resistant starch diet.
Optimal range: 10 - 100 Units
LEARN MOREReference range: None Detected, Very Low, Low, Moderate, High
The Lactalbumin marker measures IgG antibodies to alpha-lactalbumin, a whey protein found in milk. Results are reported as none detected, very low, low, moderate, or high. These levels reflect immune exposure and recognition rather than lactose intolerance or a true milk allergy. Interpretation should consider overall dairy intake and symptom history.
