From the breakdown of hydroxykynurenine via kynurenine aminotransferases (KAT) +B6
- Elevated xanthurenic acid has been noted with B6 deficiency.
- Elevated levels have been noted as more significant in oral contraceptive users in studies using a tryptophan load.
- In a mathematical model without a tryptophan load, a moderate vitamin B6 deficiency resulted in a slight increase in xanthurenic acid and a slight decrease in kynurenic acid and anthranilate.
- Without a tryptophan load, urine kynurenine and xanthurenic acid both increase in a pronounced B6 deficiency.
- Animal studies found a low urinary excretion ratio of xanthurenic acid/ kynurenic acid as a possible marker of niacin need, proposing that levels may increase with repletion.
- Niacin (vitamin B3) is a product of tryptophan degradation. In alcoholic pellagra patients, the tryptophanniacin pathway is inhibited after the 3-hydroxyanthranilate oxidase step, which can result in increased kynurenic acid, and decreased xanthurenic acid and quinolinic acid.
Understand and improve your laboratory results with our health dashboard.
Upload your lab reports and get interpretation today.
Our technology helps to understand, combine, track, organize, and act on your medical lab test results.
Because this pathway is heavily dependent on vitamin B6, elevations of xanthurenic acid can reflect a functional need for vitamin B6.
Kynurenine pathway metabolites may also become elevated when there are needs for vitamin B3.
Elevations in urinary xanthurenic acid are seen with increased intake of tryptophan, and in high estrogen states. Pregnancy and oral contraceptive use is associated with elevated levels of urinary xanthurenic acid where a functional nutrient need for B-vitamins is pronounced.
Abnormalities in the kynurenine pathway have been associated with many clinical conditions including immune suppression, cancer, and inflammatory conditions. Administration of vitamin B6 can decrease xanthurenic acid excretion.
Interpret Your Lab Results
Upload your lab report and we’ll interpret and provide you with recomendations today.Get Started
Get Started With Our Personal Plan
Are You a Health Professional?
Get started with our professional plan
Welcome to Healthmatters Pro.
Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more
for health professionals
$45 per month
1-Methylhistidine, 1-Methylhistidine (Plasma), 2-,3-, and 4-Methylhippuric acid, 2-Methylhippuric Acid, 2-Methylsuccinic Acid, 3,4-Dihydroxyhydrocinnamic Acid, 3,5-Dihydroxybenzoic Acid, 3-Methylhistidine (Plasma), 3-Phenylpropionylglycine, 4-Hydroxybenzoic Acid, 4-Hydroxyphenylacetic Acid, 4-Hydroxyphenylpyruvic Acid, 5-Hydroxyindoleacetic Acid, 8-Hydroxy-2'-deoxyguanosine, a-Hydroxybutyric Acid, a-Keto-b-methylvaleric Acid, a-Ketobutyric Acid, a-Ketoglutaric Acid, a-Ketoisocaproic Acid, a-Ketoisovaleric Acid, a-Aminoadipic Acid (Plasma), Adipic Acid, Alanine, Alanine (Plasma), Aldosterone, Anserine (Plasma), Anthranilic Acid, Arabinitol, Arginine (Plasma), Arginosuccinic Acid, Arginosuccinic Acid (Plasma), Asparagine (Plasma), Aspartic Acid (Plasma), b-Hydroxybutyric Acid, b-Hydroxyisovaleric Acid, b-Alanine (Plasma), Benzoic Acid, Benzoylform, Branched Chain Alpha-Keto Organic Acids, Carnosine, Carnosine (Plasma), cis-Aconitic Acid, Citric Acid, Citrulline (Plasma), Cortisol, Cortisone, Creatinine, Cystathionine (Plasma), Cystine (Plasma), D-Lactic Acid, Equol, Ethanolamine (Plasma), Ethylmalonic Acid, Formiminoglutamic Acid, Fructose, Fumaric Acid, g-Aminobutyric Acid (Plasma), Glucaric Acid, Glucose, Glutamic Acid (Plasma), Glutamine (Plasma), Glutamine / Glutamate Ratio (Plasma), Glutaric Acid, Glycine (Plasma), Glycylproline (Plasma), Hexanoylglycine, Hippuric Acid, Histidine (Plasma), Homocitrulline (Plasma), Homocystine (Plasma), Homogentisic Acid, Homovanillic Acid, Hydroxykynurenine, Hydroxyproline, Hydroxyproline (Plasma), Indoleacetic Acid, Isocitric Acid, Isoleucine/allo-Isoleucine (Plasma), KT Ratio (Plasma), Kynurenic Acid, Kynurenine (Plasma), Lactic Acid, Leucine (Plasma), Lysine (Plasma), Malic Acid, Mandelic Acid, Methionine (Plasma), Methylmalonic Acid, Microalbumin, Ornithine, Ornithine (Plasma), Orotic Acid, Oxalic Acid, pH, Phenylacetic Acid, Phenylalanine (Plasma), Phosphate, Phosphoethanolamine (Plasma), Picolinic Acid, Pimelic Acid, Proline (Plasma), Pyridoxic Acid, Pyroglutamic Acid, Pyruvic Acid, Quercetin, Quinolinic Acid, Sarcosine (Plasma), Sebacic Acid, Serine (Plasma), Suberic Acid, Suberylglycine, Succinic Acid, Sulfocysteine (Plasma), Tartaric Acid, Taurine (Plasma), Threonine (Plasma), Total Branched Chain Amino Acids (Plasma), Tryptophan (Plasma), Tyrosine (Plasma), Valine (Plasma), Vannilylmandelic Acid, Xanthurenic Acid