Component

Human dietary phenylalanine requirement estimate

Context-specific entity; species, compartment and exposure are stated on each claim.

2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

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.

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.

Recorded relationships

What acts on it

  1. A tracer study in healthy Indian adults consuming no tyrosine estimated mean phenylalanine requirement at about 38 mg/kg/day.

    L-Phenylalanine → Human dietary phenylalanine requirement estimate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human indicator amino-acid oxidation/balance feeding study without dietary tyrosine.
    limitations
    Population and protocol differ from the older-adult excess-tyrosine study; different estimates are not treated as a scientific contradiction.
    nutrient_topic
    L-Phenylalanine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Phenylalanine
    plain_language
    When tyrosine is absent, phenylalanine must cover an additional metabolic demand.
    primary_references
    The daily phenylalanine requirement of healthy Indian adults. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16762944/ · DOI 10.1093/ajcn/83.6.1331

    L-Phenylalanine: transport, protein synthesis, cofactor recycling and cross-nutrient mechanisms (2026-09-19) · lines 270–276

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human indicator amino-acid oxidation/balance feeding study without dietary tyrosine. · source_derived_draft · unverified_draft

    ## l-phenylalanine-no-tyrosine-requirement When tyrosine is absent, phenylalanine must cover an additional metabolic demand. A tracer study in healthy Indian adults consuming no tyrosine estimated mean phenylalanine requirement at about 38 mg/kg/day. Model: Human indicator amino-acid oxidation/balance feeding study without dietary tyrosine. Limitations: Population and protocol differ from the older-adult excess-tyrosine study; different estimates are not treated as a scientific contradiction. Evidence access: Primary abstract The daily phenylalanine requirement of healthy Indian adults. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16762944/ · DOI 10.1093/ajcn/83.6.1331
    Complete structured claim and evidence

  2. With excess tyrosine supplied, indicator-amino-acid oxidation in twelve older adults across 66 studies estimated mean phenylalanine requirement at 9.03 mg/kg/day and its upper 95% confidence limit at 15.9 mg/kg/day.

    L-Tyrosine → Human dietary phenylalanine requirement estimate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human tracer feeding study with phenylalanine intakes 7.2–40 mg/kg/day and excess tyrosine.
    limitations
    This conditional estimate is not a universal intake target or evidence that tyrosine replaces phenylalanine in proteins.
    nutrient_topic
    L-Phenylalanine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Phenylalanine
    plain_language
    Supplying tyrosine changes how much phenylalanine must be reserved for making it.
    primary_references
    The Phenylalanine Requirement of Elderly Men and Women Measured by Direct 13C Carbon Oxidation Method Is Similar to That of Young Adults. · 2019 · https://pubmed.ncbi.nlm.nih.gov/31271193/ · DOI 10.1093/jn/nxz137

    L-Phenylalanine: transport, protein synthesis, cofactor recycling and cross-nutrient mechanisms (2026-09-19) · lines 262–268

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human tracer feeding study with phenylalanine intakes 7.2–40 mg/kg/day and excess tyrosine. · source_derived_draft · unverified_draft

    ## l-phenylalanine-tyrosine-sparing Supplying tyrosine changes how much phenylalanine must be reserved for making it. With excess tyrosine supplied, indicator-amino-acid oxidation in twelve older adults across 66 studies estimated mean phenylalanine requirement at 9.03 mg/kg/day and its upper 95% confidence limit at 15.9 mg/kg/day. Model: Human tracer feeding study with phenylalanine intakes 7.2–40 mg/kg/day and excess tyrosine. Limitations: This conditional estimate is not a universal intake target or evidence that tyrosine replaces phenylalanine in proteins. Evidence access: Primary abstract The Phenylalanine Requirement of Elderly Men and Women Measured by Direct 13C Carbon Oxidation Method Is Similar to That of Young Adults. · 2019 · https://pubmed.ncbi.nlm.nih.gov/31271193/ · DOI 10.1093/jn/nxz137
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

    Evidence, AI assistance and curation standards