Component
Urinary 2PY excretion
Urinary 2PY excretion. The model and exposure of each linked claim define its scope.
1 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
How nutrients influence it
Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
How nutrients reach it in more than one step
Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.
Tracing routes…
What it does
Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.
What acts on it
Urinary 2PY below 1.2 mg/day tracked the lowest intake; the urinary 2PY-to-methyl-nicotinamide ratio performed less well than individual metabolite outputs and missed the 10.1-NE/day restriction.
Experimental context and source evidence
- availability_state
- nutrient_deficiency Imported condition classification; unverified.
- cross_nutrient
- N1-methyl-2-pyridone-5-carboxamide (2PY) (measured_metabolite)
- evidence_span
- {"source_cache": "artifacts/niacin-clinical-sources/jacob1989.abstract.txt", "locator": "Indexed primary abstract", "file_sha256": "749fc69d8d6cb1ba79a0b17e38e9300611713e3939224ba9ac809cef91c7a64c", "start_char": 0, "end_char": 1463, "text_sha256": "749fc69d8d6cb1ba79a0b17e38e9300611713e3939224ba9ac809cef91c7a64c"}
- experimental_model
- Controlled metabolic-unit feeding of young men for 11 weeks
- exposure
- 6.1–32 NE/day; oral nicotinamide test doses
- limitations
- Small controlled male metabolic-unit study. Erythrocytes are not every tissue; historical adequate intake is not a current recommendation. Jacob and Fu reports may describe related participants and are not counted as independent trials. Historical NMN abbreviation means N1-methylnicotinamide, not nicotinamide mononucleotide. Urinary output is not a universal diagnostic cutoff.
- nutrient_topic
- Niacin research collection; topical membership is not evidence of a direct dietary effect. · Niacin (vitamin B3)
- organism
- Homo sapiens
- plain_language
- Individual urine measurements were more informative than assuming their ratio was a better marker.
- primary_references
- [nia-clin-jacob1989] Biochemical markers for assessment of niacin status in young men: urinary and blood levels of niacin metabolites. (1989). https://pubmed.ncbi.nlm.nih.gov/2522982/ DOI: 10.1093/jn/119.4.591
- tissue_or_cell_type
- Urine and plasma
- trigger_kind
- nutrient_deficiency Imported condition classification; unverified.
Niacin: NAD metabolism, deficiency and nutrient interactions (2026-09-17) · lines 1163–1175
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Controlled metabolic-unit feeding of young men for 11 weeks · source_derived_draft · unverified_draft
### nia-clin-urine-2py-restriction Urinary 2PY below 1.2 mg/day tracked the lowest intake; the urinary 2PY-to-methyl-nicotinamide ratio performed less well than individual metabolite outputs and missed the 10.1-NE/day restriction. Condition category: nutrient_deficiency nutrient_topic: Niacin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Individual urine measurements were more informative than assuming their ratio was a better marker. organism: Homo sapiens tissue_or_cell_type: Urine and plasma experimental_model: Controlled metabolic-unit feeding of young men for 11 weeks limitations: Small controlled male metabolic-unit study. Erythrocytes are not every tissue; historical adequate intake is not a current recommendation. Jacob and Fu reports may describe related participants and are not counted as independent trials. Historical NMN abbreviation means N1-methylnicotinamide, not nicotinamide mononucleotide. Urinary output is not a universal diagnostic cutoff. exposure: 6.1–32 NE/day; oral nicotinamide test doses cross_nutrient: N1-methyl-2-pyridone-5-carboxamide (2PY) (measured_metabolite) evidence_span: {"source_cache": "artifacts/niacin-clinical-sources/jacob1989.abstract.txt", "locator": "Indexed primary abstract", "file_sha256": "749fc69d8d6cb1ba79a0b17e38e9300611713e3939224ba9ac809cef91c7a64c", "start_char": 0, "end_char": 1463, "text_sha256": "749fc69d8d6cb1ba79a0b17e38e9300611713e3939224ba9ac809cef91c7a64c"} [nia-clin-jacob1989] Biochemical markers for assessment of niacin status in young men: urinary and blood levels of niacin metabolites. (1989). https://pubmed.ncbi.nlm.nih.gov/2522982/ DOI: 10.1093/jn/119.4.591
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.