Component

Vitamin B6

Vitamin B6 is a family of related compounds. Its active cofactor forms support amino-acid reactions, neurotransmitter synthesis, heme production and other pathways. Individual forms, deficiency, genetic impairment and excess exposure are recorded separately. Vitamin B6 vitamer family; pyridoxine, pyridoxal, pyridoxamine and their phosphorylated forms remain separate chemical entities.

23 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 it acts on

  1. IL-2 production declined during depletion; immune indices returned to baseline after the third repletion stage.

    Vitamin B6 → IL-2 source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Eight healthy older adults in sequential dietary depletion and repletion experiment.
    exposure
    Depletion up to 20 days, then three 21-day repletion stages; final short 50 mg/day phase. Repletion-stage intakes are historical experimental context.
    limitations
    Recovery occurred during a sequence of increasing intakes; no universal individual requirement or treatment dose follows.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    The observed immune changes were reversible with restored intake.
    primary_references
    [b6-meydani1991] Vitamin B-6 deficiency impairs interleukin 2 production and lymphocyte proliferation in elderly adults (1991). https://pubmed.ncbi.nlm.nih.gov/2021134/ DOI: 10.1093/ajcn/53.5.1275
    tissue_or_cell_type
    Ex-vivo human immune-cell assays
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1681–1691

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eight healthy older adults in sequential dietary depletion and repletion experiment. · source_derived_draft · unverified_draft

    ### b6-depletion-il2 IL-2 production declined during depletion; immune indices returned to baseline after the third repletion stage. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The observed immune changes were reversible with restored intake. organism: Homo sapiens tissue_or_cell_type: Ex-vivo human immune-cell assays experimental_model: Eight healthy older adults in sequential dietary depletion and repletion experiment. limitations: Recovery occurred during a sequence of increasing intakes; no universal individual requirement or treatment dose follows. exposure: Depletion up to 20 days, then three 21-day repletion stages; final short 50 mg/day phase. Repletion-stage intakes are historical experimental context. [b6-meydani1991] Vitamin B-6 deficiency impairs interleukin 2 production and lymphocyte proliferation in elderly adults (1991). https://pubmed.ncbi.nlm.nih.gov/2021134/ DOI: 10.1093/ajcn/53.5.1275
    Complete structured claim and evidence

  2. Depletion reduced circulating lymphocyte number/percentage and lymphocyte responses to T- and B-cell mitogens.

    Vitamin B6 → Circulating lymphocyte count source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Eight healthy older adults in sequential dietary depletion and repletion experiment.
    exposure
    Depletion up to 20 days, then three 21-day repletion stages; final short 50 mg/day phase. Repletion-stage intakes are historical experimental context.
    limitations
    Eight-person sequential design; not evidence that supplementing adequate people prevents infection.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    Too little B6 weakened measured immune-cell responses in this experiment.
    primary_references
    [b6-meydani1991] Vitamin B-6 deficiency impairs interleukin 2 production and lymphocyte proliferation in elderly adults (1991). https://pubmed.ncbi.nlm.nih.gov/2021134/ DOI: 10.1093/ajcn/53.5.1275
    tissue_or_cell_type
    Human circulating lymphocytes and ex-vivo cultures
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1669–1679

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Eight healthy older adults in sequential dietary depletion and repletion experiment. · source_derived_draft · unverified_draft

    ### b6-depletion-lymphocytes Depletion reduced circulating lymphocyte number/percentage and lymphocyte responses to T- and B-cell mitogens. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Too little B6 weakened measured immune-cell responses in this experiment. organism: Homo sapiens tissue_or_cell_type: Human circulating lymphocytes and ex-vivo cultures experimental_model: Eight healthy older adults in sequential dietary depletion and repletion experiment. limitations: Eight-person sequential design; not evidence that supplementing adequate people prevents infection. exposure: Depletion up to 20 days, then three 21-day repletion stages; final short 50 mg/day phase. Repletion-stage intakes are historical experimental context. [b6-meydani1991] Vitamin B-6 deficiency impairs interleukin 2 production and lymphocyte proliferation in elderly adults (1991). https://pubmed.ncbi.nlm.nih.gov/2021134/ DOI: 10.1093/ajcn/53.5.1275
    Complete structured claim and evidence

  3. Dietary B6 restriction increased plasma cystathionine by 124% while plasma PLP fell from 55.1 to 22.6 nmol/L.

    Vitamin B6 → Cystathionine source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements.
    exposure
    Four weeks below 0.5 mg/day dietary B6; overnight-fasted tracer protocol.
    limitations
    Pool size alone cannot identify the limiting enzyme or quantify pathway flux.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    A pathway intermediate accumulated even though the whole pathway did not simply stop.
    primary_references
    [b6-davis2006] Plasma glutathione and cystathionine concentrations are elevated but cysteine flux is unchanged by dietary vitamin B-6 restriction in young men and women (2006). https://pubmed.ncbi.nlm.nih.gov/16424114/ DOI: 10.1093/jn/136.2.373
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1309–1319

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements. · source_derived_draft · unverified_draft

    ### b6-fasting-cystathionine-pool Dietary B6 restriction increased plasma cystathionine by 124% while plasma PLP fell from 55.1 to 22.6 nmol/L. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A pathway intermediate accumulated even though the whole pathway did not simply stop. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements. limitations: Pool size alone cannot identify the limiting enzyme or quantify pathway flux. exposure: Four weeks below 0.5 mg/day dietary B6; overnight-fasted tracer protocol. [b6-davis2006] Plasma glutathione and cystathionine concentrations are elevated but cysteine flux is unchanged by dietary vitamin B-6 restriction in young men and women (2006). https://pubmed.ncbi.nlm.nih.gov/16424114/ DOI: 10.1093/jn/136.2.373
    Complete structured claim and evidence

  4. Whole-body cysteine flux and fractional cystathionine synthesis were unchanged; transsulfuration-derived cysteine synthesis was below detection in this fasting protocol.

    Vitamin B6 → Whole-body cysteine flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements.
    exposure
    Four weeks below 0.5 mg/day dietary B6; overnight-fasted tracer protocol.
    limitations
    Below detection is not zero flux, nor proof that transsulfuration was unchanged.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    The investigators could measure cysteine turnover but could not reliably quantify one specific input route.
    primary_references
    [b6-davis2006] Plasma glutathione and cystathionine concentrations are elevated but cysteine flux is unchanged by dietary vitamin B-6 restriction in young men and women (2006). https://pubmed.ncbi.nlm.nih.gov/16424114/ DOI: 10.1093/jn/136.2.373
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1334–1344

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements. · source_derived_draft · unverified_draft

    ### b6-fasting-cysteine-flux Whole-body cysteine flux and fractional cystathionine synthesis were unchanged; transsulfuration-derived cysteine synthesis was below detection in this fasting protocol. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The investigators could measure cysteine turnover but could not reliably quantify one specific input route. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements. limitations: Below detection is not zero flux, nor proof that transsulfuration was unchanged. exposure: Four weeks below 0.5 mg/day dietary B6; overnight-fasted tracer protocol. [b6-davis2006] Plasma glutathione and cystathionine concentrations are elevated but cysteine flux is unchanged by dietary vitamin B-6 restriction in young men and women (2006). https://pubmed.ncbi.nlm.nih.gov/16424114/ DOI: 10.1093/jn/136.2.373
    Complete structured claim and evidence

  5. Plasma total glutathione rose 38% during restriction; plasma cysteine, homocysteine and CRP did not significantly change.

    Vitamin B6 → Plasma total glutathione concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6-dependent sulfur metabolism connects to glutathione, with blood and cellular pools distinguished.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements.
    exposure
    Four weeks below 0.5 mg/day dietary B6; overnight-fasted tracer protocol.
    limitations
    Plasma total glutathione is not intracellular reduced GSH, tissue antioxidant capacity or synthesis rate.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    This experiment did not find a universal glutathione collapse.
    primary_references
    [b6-davis2006] Plasma glutathione and cystathionine concentrations are elevated but cysteine flux is unchanged by dietary vitamin B-6 restriction in young men and women (2006). https://pubmed.ncbi.nlm.nih.gov/16424114/ DOI: 10.1093/jn/136.2.373
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1321–1332

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements. · source_derived_draft · unverified_draft

    ### b6-fasting-total-glutathione Plasma total glutathione rose 38% during restriction; plasma cysteine, homocysteine and CRP did not significantly change. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: This experiment did not find a universal glutathione collapse. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–30), controlled restriction with fasting stable-isotope measurements. limitations: Plasma total glutathione is not intracellular reduced GSH, tissue antioxidant capacity or synthesis rate. exposure: Four weeks below 0.5 mg/day dietary B6; overnight-fasted tracer protocol. cross_nutrient: B6-dependent sulfur metabolism connects to glutathione, with blood and cellular pools distinguished. [b6-davis2006] Plasma glutathione and cystathionine concentrations are elevated but cysteine flux is unchanged by dietary vitamin B-6 restriction in young men and women (2006). https://pubmed.ncbi.nlm.nih.gov/16424114/ DOI: 10.1093/jn/136.2.373
    Complete structured claim and evidence

  6. Cystathionine fractional synthesis increased by a mean 12% in eight of nine participants; plasma concentration rose 142 to 236 nmol/L.

    Vitamin B6 → Cystathionine fractional synthesis rate source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics.
    exposure
    28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L.
    limitations
    Fractional synthesis, pool size and total flux are distinct measurements.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    A faster fractional rate for an intermediate can coexist with preserved overall pathway throughput.
    primary_references
    [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1385–1395

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. · source_derived_draft · unverified_draft

    ### b6-fed-cystathionine-synthesis Cystathionine fractional synthesis increased by a mean 12% in eight of nine participants; plasma concentration rose 142 to 236 nmol/L. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A faster fractional rate for an intermediate can coexist with preserved overall pathway throughput. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. limitations: Fractional synthesis, pool size and total flux are distinct measurements. exposure: 28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L. [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    Complete structured claim and evidence

  7. Mean postprandial homocysteine remethylation did not significantly change after restriction, with substantial individual variation.

    Vitamin B6 → Homocysteine remethylation flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6 intersects methionine/folate metabolism; this experiment does not establish B12 or folate depletion.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics.
    exposure
    28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L.
    limitations
    Null group means do not establish identical responses or preserved DNA methylation in every tissue.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    Lower B6 did not make this measured process uniformly fail.
    primary_references
    [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1346–1357

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. · source_derived_draft · unverified_draft

    ### b6-fed-remethylation-preserved Mean postprandial homocysteine remethylation did not significantly change after restriction, with substantial individual variation. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Lower B6 did not make this measured process uniformly fail. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. limitations: Null group means do not establish identical responses or preserved DNA methylation in every tissue. exposure: 28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L. cross_nutrient: B6 intersects methionine/folate metabolism; this experiment does not establish B12 or folate depletion. [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    Complete structured claim and evidence

  8. Mean postprandial transmethylation did not significantly change after restriction, with substantial individual variation.

    Vitamin B6 → Methionine-cycle transmethylation flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6 intersects methionine/folate metabolism; this experiment does not establish B12 or folate depletion.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics.
    exposure
    28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L.
    limitations
    Null group means do not establish identical responses or preserved DNA methylation in every tissue.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    Lower B6 did not make this measured process uniformly fail.
    primary_references
    [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1359–1370

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. · source_derived_draft · unverified_draft

    ### b6-fed-transmethylation-preserved Mean postprandial transmethylation did not significantly change after restriction, with substantial individual variation. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Lower B6 did not make this measured process uniformly fail. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. limitations: Null group means do not establish identical responses or preserved DNA methylation in every tissue. exposure: 28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L. cross_nutrient: B6 intersects methionine/folate metabolism; this experiment does not establish B12 or folate depletion. [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    Complete structured claim and evidence

  9. Mean postprandial total transsulfuration did not significantly change after restriction, with substantial individual variation.

    Vitamin B6 → Total transsulfuration flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6 intersects methionine/folate metabolism; this experiment does not establish B12 or folate depletion.
    experimental_model
    Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics.
    exposure
    28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L.
    limitations
    Null group means do not establish identical responses or preserved DNA methylation in every tissue.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    Lower B6 did not make this measured process uniformly fail.
    primary_references
    [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1372–1383

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. · source_derived_draft · unverified_draft

    ### b6-fed-transsulfuration-preserved Mean postprandial total transsulfuration did not significantly change after restriction, with substantial individual variation. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Lower B6 did not make this measured process uniformly fail. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Nine healthy adults (five women, four men; ages 20–35), repeated postprandial isotope kinetics. limitations: Null group means do not establish identical responses or preserved DNA methylation in every tissue. exposure: 28 days dietary B6 restriction; plasma PLP49±4 to 19±2 nmol/L. cross_nutrient: B6 intersects methionine/folate metabolism; this experiment does not establish B12 or folate depletion. [b6-lamers2011] Moderate vitamin B-6 restriction does not alter postprandial methionine cycle rates of remethylation, transmethylation, and total transsulfuration but increases the fractional synthesis rate of cystathionine in healthy young men and women (2011). https://pubmed.ncbi.nlm.nih.gov/21430249/ DOI: 10.3945/jn.110.134197
    Complete structured claim and evidence

  10. Restriction did not significantly change glycine cleavage or serine synthesis from GCS-derived one-carbon units.

    Vitamin B6 → Glycine cleavage flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6-dependent glycine cleavage supplies folate one-carbon chemistry.
    experimental_model
    Thirteen healthy adults (seven men, six women; ages 20–39); glycine and leucine stable-isotope infusion.
    exposure
    Moderate dietary B6 restriction; plasma PLP55±4 to 23±1 nmol/L.
    limitations
    Whole-body kinetics do not resolve separate organs or prove severe deficiency harmless.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    This folate-linked carbon supply remained measurable despite lower blood B6.
    primary_references
    [b6-lamers2009] Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women (2009). https://pubmed.ncbi.nlm.nih.gov/19158217/ DOI: 10.3945/jn.108.099184
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1397–1408

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Thirteen healthy adults (seven men, six women; ages 20–39); glycine and leucine stable-isotope infusion. · source_derived_draft · unverified_draft

    ### b6-glycine-cleavage-resilience Restriction did not significantly change glycine cleavage or serine synthesis from GCS-derived one-carbon units. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: This folate-linked carbon supply remained measurable despite lower blood B6. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Thirteen healthy adults (seven men, six women; ages 20–39); glycine and leucine stable-isotope infusion. limitations: Whole-body kinetics do not resolve separate organs or prove severe deficiency harmless. exposure: Moderate dietary B6 restriction; plasma PLP55±4 to 23±1 nmol/L. cross_nutrient: B6-dependent glycine cleavage supplies folate one-carbon chemistry. [b6-lamers2009] Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women (2009). https://pubmed.ncbi.nlm.nih.gov/19158217/ DOI: 10.3945/jn.108.099184
    Complete structured claim and evidence

  11. SHMT-mediated glycine-to-serine conversion increased 182 to 205 micromol/kg/hour during restriction, accompanied by higher plasma glycine.

    Vitamin B6 → Glycine-to-serine flux source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6 and folate participate in a reversible reaction; flux direction matters.
    experimental_model
    Thirteen healthy adults (seven men, six women; ages 20–39); glycine and leucine stable-isotope infusion.
    exposure
    Moderate dietary B6 restriction; plasma PLP55±4 to 23±1 nmol/L.
    limitations
    Do not substitute the reverse serine-to-glycine direction or identify the responsible SHMT compartment from whole-body data.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    The measured direction ran faster, rather than shutting down.
    primary_references
    [b6-lamers2009] Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women (2009). https://pubmed.ncbi.nlm.nih.gov/19158217/ DOI: 10.3945/jn.108.099184
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1410–1421

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Thirteen healthy adults (seven men, six women; ages 20–39); glycine and leucine stable-isotope infusion. · source_derived_draft · unverified_draft

    ### b6-glycine-serine-flux-increase SHMT-mediated glycine-to-serine conversion increased 182 to 205 micromol/kg/hour during restriction, accompanied by higher plasma glycine. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The measured direction ran faster, rather than shutting down. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Thirteen healthy adults (seven men, six women; ages 20–39); glycine and leucine stable-isotope infusion. limitations: Do not substitute the reverse serine-to-glycine direction or identify the responsible SHMT compartment from whole-body data. exposure: Moderate dietary B6 restriction; plasma PLP55±4 to 23±1 nmol/L. cross_nutrient: B6 and folate participate in a reversible reaction; flux direction matters. [b6-lamers2009] Moderate dietary vitamin B-6 restriction raises plasma glycine and cystathionine concentrations while minimally affecting the rates of glycine turnover and glycine cleavage in healthy men and women (2009). https://pubmed.ncbi.nlm.nih.gov/19158217/ DOI: 10.3945/jn.108.099184
    Complete structured claim and evidence

  12. Vitamin B6 administration lowered plasma cystathionine in the reported CTH Thr67Ile homozygote.

    Vitamin B6 → Plasma cystathionine concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    evidence_location
    p.Thr67Ile section; Supplemental Table 3
    experimental_model
    Human families; expressed human CTH variants
    exposure
    Vitamin B6 administration reported for patient 2927; observational case context
    limitations
    Single genotype-specific case; not a treatment recommendation or evidence of deficiency.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    B6 responsiveness occurred in this particular enzyme genotype.
    primary_references
    [b6-cth-2009] Cystathionine gamma-lyase: Clinical, metabolic, genetic, and structural studies. (2009). https://pmc.ncbi.nlm.nih.gov/articles/PMC2752209/ DOI: 10.1016/j.ymgme.2009.04.001
    tissue_or_cell_type
    Human plasma
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 577–588

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human families; expressed human CTH variants · source_derived_draft · unverified_draft

    ### b6-met-cth-t67i-clinical Vitamin B6 administration lowered plasma cystathionine in the reported CTH Thr67Ile homozygote. Condition category: machinery_impairment nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: B6 responsiveness occurred in this particular enzyme genotype. organism: Homo sapiens tissue_or_cell_type: Human plasma experimental_model: Human families; expressed human CTH variants limitations: Single genotype-specific case; not a treatment recommendation or evidence of deficiency. exposure: Vitamin B6 administration reported for patient 2927; observational case context evidence_location: p.Thr67Ile section; Supplemental Table 3 [b6-cth-2009] Cystathionine gamma-lyase: Clinical, metabolic, genetic, and structural studies. (2009). https://pmc.ncbi.nlm.nih.gov/articles/PMC2752209/ DOI: 10.1016/j.ymgme.2009.04.001
    Complete structured claim and evidence

  13. Under niacin-free feeding, B6-free rats had lower apparent tryptophan-to-niacin conversion than rats receiving B6.

    Vitamin B6 → Apparent tryptophan-to-niacin conversion from urinary metabolites source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    Dietary B6 status affected apparent tryptophan-to-niacin conversion.
    experimental_model
    Young male Wistar rats; four controlled diets for 19 days
    exposure
    Young male Wistar rats; 19-day diets; conversion contrast within niacin-free groups
    limitations
    Apparent urinary conversion, not net synthesis or a human requirement.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Rattus norvegicus
    plain_language
    B6 shortage reduced this dietary study's estimate of niacin production from tryptophan.
    primary_references
    [b6-niacin-1995] Effects of Vitamin B6 Deficiency on the Conversion Ratio of Tryptophan to Niacin (1995). https://doi.org/10.1271/bbb.59.2060 DOI: 10.1271/bbb.59.2060
    tissue_or_cell_type
    Whole-animal dietary intake and urine
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 898–909

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Young male Wistar rats; four controlled diets for 19 days · source_derived_draft · unverified_draft

    ### b6-met-rat-niacin-conversion Under niacin-free feeding, B6-free rats had lower apparent tryptophan-to-niacin conversion than rats receiving B6. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: B6 shortage reduced this dietary study's estimate of niacin production from tryptophan. organism: Rattus norvegicus tissue_or_cell_type: Whole-animal dietary intake and urine experimental_model: Young male Wistar rats; four controlled diets for 19 days limitations: Apparent urinary conversion, not net synthesis or a human requirement. cross_nutrient: Dietary B6 status affected apparent tryptophan-to-niacin conversion. exposure: Young male Wistar rats; 19-day diets; conversion contrast within niacin-free groups [b6-niacin-1995] Effects of Vitamin B6 Deficiency on the Conversion Ratio of Tryptophan to Niacin (1995). https://doi.org/10.1271/bbb.59.2060 DOI: 10.1271/bbb.59.2060
    Complete structured claim and evidence

  14. Both B6-free rat diet groups showed substantially increased urinary xanthurenate relative to B6-containing groups.

    Vitamin B6 → Urinary xanthurenate excretion source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6 and tryptophan metabolism.
    experimental_model
    Young male Wistar rats; four controlled diets for 19 days
    exposure
    19-day controlled diets
    limitations
    The marker does not independently measure intracellular NAD.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Rattus norvegicus
    plain_language
    B6 withdrawal diverted this urinary tryptophan-metabolism readout.
    primary_references
    [b6-niacin-1995] Effects of Vitamin B6 Deficiency on the Conversion Ratio of Tryptophan to Niacin (1995). https://doi.org/10.1271/bbb.59.2060 DOI: 10.1271/bbb.59.2060
    tissue_or_cell_type
    Urine
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 911–922

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Young male Wistar rats; four controlled diets for 19 days · source_derived_draft · unverified_draft

    ### b6-met-rat-xanthurenate Both B6-free rat diet groups showed substantially increased urinary xanthurenate relative to B6-containing groups. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: B6 withdrawal diverted this urinary tryptophan-metabolism readout. organism: Rattus norvegicus tissue_or_cell_type: Urine experimental_model: Young male Wistar rats; four controlled diets for 19 days limitations: The marker does not independently measure intracellular NAD. cross_nutrient: B6 and tryptophan metabolism. exposure: 19-day controlled diets [b6-niacin-1995] Effects of Vitamin B6 Deficiency on the Conversion Ratio of Tryptophan to Niacin (1995). https://doi.org/10.1271/bbb.59.2060 DOI: 10.1271/bbb.59.2060
    Complete structured claim and evidence

  15. In the 2010 cointervention trial, plasma IL-6 and TNF declined within the B6-plus-folic-acid group over 12 weeks.

    Vitamin B6 → IL6 source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Folic acid was given to both arms; no biochemical B6–folate synergy established.
    experimental_model
    Single-blind randomized cointervention in 35 RA patients: 15 control and 20 B6.
    exposure
    Both groups folic acid 5 mg/day; B6 group also 100 mg/day for 12 weeks. Reported cytokine result is within-group change.
    limitations
    The accessed abstract reports within-group significance, not a demonstrated between-group change contrast. Plasma concentration differs from cytokine production; no automatic contradiction with 2005.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    A different trial found a cytokine signal under a different exposure and measurement design.
    primary_references
    [b6-huang2010] Vitamin B(6) supplementation improves pro-inflammatory responses in patients with rheumatoid arthritis (2010). https://pubmed.ncbi.nlm.nih.gov/20571496/ DOI: 10.1038/ejcn.2010.107
    tissue_or_cell_type
    Human blood and whole-body measurements

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1510–1521

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Single-blind randomized cointervention in 35 RA patients: 15 control and 20 B6. · source_derived_draft · unverified_draft

    ### b6-ra-cointervention-cytokine-signal In the 2010 cointervention trial, plasma IL-6 and TNF declined within the B6-plus-folic-acid group over 12 weeks. Condition category: normal nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A different trial found a cytokine signal under a different exposure and measurement design. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Single-blind randomized cointervention in 35 RA patients: 15 control and 20 B6. limitations: The accessed abstract reports within-group significance, not a demonstrated between-group change contrast. Plasma concentration differs from cytokine production; no automatic contradiction with 2005. exposure: Both groups folic acid 5 mg/day; B6 group also 100 mg/day for 12 weeks. Reported cytokine result is within-group change. cross_nutrient: Folic acid was given to both arms; no biochemical B6–folate synergy established. [b6-huang2010] Vitamin B(6) supplementation improves pro-inflammatory responses in patients with rheumatoid arthritis (2010). https://pubmed.ncbi.nlm.nih.gov/20571496/ DOI: 10.1038/ejcn.2010.107
    Complete structured claim and evidence

  16. Plasma creatine decreased 40% in both meal states; creatinine fell 9% and dimethylglycine 16% postprandially.

    Vitamin B6 → Creatine source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    Plasma metabolites connect B6 status with one-carbon metabolism without establishing a complete causal chain.
    experimental_model
    Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling.
    exposure
    28 days below 0.35 mg/day B6. Related restriction research program; do not count paper totals as independent trial replications.
    limitations
    This does not establish exhausted SAM, impaired muscle phosphocreatine or a direct PLP requirement for creatine methylation.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    B6 restriction changed selected methylation-related metabolites.
    primary_references
    [b6-dasilva2013] Metabolite profile analysis reveals functional effects of 28-day vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women (2013). https://pubmed.ncbi.nlm.nih.gov/23966327/ DOI: 10.3945/jn.113.180588
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1423–1434

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling. · source_derived_draft · unverified_draft

    ### b6-restriction-creatine-profile Plasma creatine decreased 40% in both meal states; creatinine fell 9% and dimethylglycine 16% postprandially. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: B6 restriction changed selected methylation-related metabolites. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling. limitations: This does not establish exhausted SAM, impaired muscle phosphocreatine or a direct PLP requirement for creatine methylation. exposure: 28 days below 0.35 mg/day B6. Related restriction research program; do not count paper totals as independent trial replications. cross_nutrient: Plasma metabolites connect B6 status with one-carbon metabolism without establishing a complete causal chain. [b6-dasilva2013] Metabolite profile analysis reveals functional effects of 28-day vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women (2013). https://pubmed.ncbi.nlm.nih.gov/23966327/ DOI: 10.3945/jn.113.180588
    Complete structured claim and evidence

  17. 3-Hydroxykynurenine increased 39% fasting and 34% after meals; kynurenic acid decreased 22% and 20%, respectively.

    Vitamin B6 → 3-Hydroxy-L-kynurenine source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    B6-dependent kynurenine reactions intersect the tryptophan-to-niacin network; conversion to NAD was not measured.
    experimental_model
    Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling.
    exposure
    28 days below 0.35 mg/day B6. Related restriction research program; do not count paper totals as independent trial replications.
    limitations
    Does not measure brain neurotransmitters, tissue NAD synthesis or diagnose niacin deficiency.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    Different branches of tryptophan processing left a detectable blood pattern.
    primary_references
    [b6-dasilva2013] Metabolite profile analysis reveals functional effects of 28-day vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women (2013). https://pubmed.ncbi.nlm.nih.gov/23966327/ DOI: 10.3945/jn.113.180588
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1436–1447

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling. · source_derived_draft · unverified_draft

    ### b6-restriction-kynurenine-profile 3-Hydroxykynurenine increased 39% fasting and 34% after meals; kynurenic acid decreased 22% and 20%, respectively. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Different branches of tryptophan processing left a detectable blood pattern. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling. limitations: Does not measure brain neurotransmitters, tissue NAD synthesis or diagnose niacin deficiency. exposure: 28 days below 0.35 mg/day B6. Related restriction research program; do not count paper totals as independent trial replications. cross_nutrient: B6-dependent kynurenine reactions intersect the tryptophan-to-niacin network; conversion to NAD was not measured. [b6-dasilva2013] Metabolite profile analysis reveals functional effects of 28-day vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women (2013). https://pubmed.ncbi.nlm.nih.gov/23966327/ DOI: 10.3945/jn.113.180588
    Complete structured claim and evidence

  18. Cystathionine increased 53% fasting and 76% postprandially; fasting serine increased 12%.

    Vitamin B6 → Cystathionine source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling.
    exposure
    28 days below 0.35 mg/day B6. Related restriction research program; do not count paper totals as independent trial replications.
    limitations
    Shared restriction research program; not an independent demonstration of each molecular enzyme defect.
    nutrient_topic
    Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B6
    organism
    Homo sapiens
    plain_language
    More material accumulated at selected points in the network.
    primary_references
    [b6-dasilva2013] Metabolite profile analysis reveals functional effects of 28-day vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women (2013). https://pubmed.ncbi.nlm.nih.gov/23966327/ DOI: 10.3945/jn.113.180588
    tissue_or_cell_type
    Human blood and whole-body measurements
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1449–1459

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling. · source_derived_draft · unverified_draft

    ### b6-restriction-serine-cystathionine-profile Cystathionine increased 53% fasting and 76% postprandially; fasting serine increased 12%. Condition category: nutrient_deficiency nutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect. plain_language: More material accumulated at selected points in the network. organism: Homo sapiens tissue_or_cell_type: Human blood and whole-body measurements experimental_model: Twenty-three healthy adults; paired pre/postprandial LC-MS/MS metabolite profiling. limitations: Shared restriction research program; not an independent demonstration of each molecular enzyme defect. exposure: 28 days below 0.35 mg/day B6. Related restriction research program; do not count paper totals as independent trial replications. [b6-dasilva2013] Metabolite profile analysis reveals functional effects of 28-day vitamin B-6 restriction on one-carbon metabolism and tryptophan catabolic pathways in healthy men and women (2013). https://pubmed.ncbi.nlm.nih.gov/23966327/ DOI: 10.3945/jn.113.180588
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. The mixture group improved clinician-rated tics more than psychoeducation in the open-label trial.

    L-Theanine plus vitamin B6, study-specific combination → Clinician-rated tic severity source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/theanine-research/35215501.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "68809f3eaf29616aa35c472872e3c510e0c8aaf23e8880c43a91f363eaad5ea2", "start_char": 0, "end_char": 1576, "text_sha256": "68809f3eaf29616aa35c472872e3c510e0c8aaf23e8880c43a91f363eaad5ea2"}
    experimental_model
    Randomized open-label comparative trial
    exposure
    Theanine plus vitamin B6 versus psychoeducation
    limitations
    No blinded placebo and no single-ingredient arms. Cannot attribute the effect to either ingredient or prove biochemical synergy.
    nutrient_topic
    L-Theanine research collection; topical membership is not evidence of a direct dietary effect. · L-Theanine
    organism
    34 children with Tourette syndrome or chronic tic disorder and anxiety
    plain_language
    This preliminary combination result does not show that B6 makes theanine work in everyone.
    primary_references
    [theanine-p35215501] Use of Nutritional Supplements Based on L-Theanine and Vitamin B6 in Children with Tourette Syndrome, with Anxiety Disorders: A Pilot Study. (2022). https://pubmed.ncbi.nlm.nih.gov/35215501/ DOI: 10.3390/nu14040852
    tissue_or_cell_type
    Clinician-rated tics and anxiety

    L-Theanine: metabolism, neural signaling, nutrient connections and human outcomes (2026-09-17) · lines 874–885

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized open-label comparative trial · source_derived_draft · unverified_draft

    ### theanine-b6-mixture-tics The mixture group improved clinician-rated tics more than psychoeducation in the open-label trial. Condition category: normal nutrient_topic: L-Theanine research collection; topical membership is not evidence of a direct dietary effect. plain_language: This preliminary combination result does not show that B6 makes theanine work in everyone. organism: 34 children with Tourette syndrome or chronic tic disorder and anxiety tissue_or_cell_type: Clinician-rated tics and anxiety experimental_model: Randomized open-label comparative trial limitations: No blinded placebo and no single-ingredient arms. Cannot attribute the effect to either ingredient or prove biochemical synergy. exposure: Theanine plus vitamin B6 versus psychoeducation evidence_span: {"source_cache": "artifacts/theanine-research/35215501.abstract.txt", "locator": "Primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "68809f3eaf29616aa35c472872e3c510e0c8aaf23e8880c43a91f363eaad5ea2", "start_char": 0, "end_char": 1576, "text_sha256": "68809f3eaf29616aa35c472872e3c510e0c8aaf23e8880c43a91f363eaad5ea2"} [theanine-p35215501] Use of Nutritional Supplements Based on L-Theanine and Vitamin B6 in Children with Tourette Syndrome, with Anxiety Disorders: A Pilot Study. (2022). https://pubmed.ncbi.nlm.nih.gov/35215501/ DOI: 10.3390/nu14040852
    Complete structured claim and evidence

  2. Mean homocysteine fell 2.4 micromol/L with the combined B vitamins and rose 0.8 micromol/L with placebo.

    Folic acid → Homocysteine source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Directly records the combined B6/B12/folic-acid exposure.
    experimental_model
    Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years.
    exposure
    Folic acid 2.5 mg, B6 50 mg and B12 1 mg/day together versus placebo; combined intervention, not isolated folate.
    limitations
    Folate, B6 and B12 were administered together; their individual contributions cannot be separated.
    nutrient_topic
    Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
    organism
    Homo sapiens
    plain_language
    The biochemical target changed in the trial.
    primary_references
    [fol-hope2006] Homocysteine lowering with folic acid and B vitamins in vascular disease (2006). https://pubmed.ncbi.nlm.nih.gov/16531613/ DOI: 10.1056/nejmoa060900
    tissue_or_cell_type
    Human blood or whole-person clinical endpoints

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1617–1628

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years. · source_derived_draft · unverified_draft

    ### fol-hope2-homocysteine Mean homocysteine fell 2.4 micromol/L with the combined B vitamins and rose 0.8 micromol/L with placebo. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: The biochemical target changed in the trial. organism: Homo sapiens tissue_or_cell_type: Human blood or whole-person clinical endpoints experimental_model: Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years. limitations: Folate, B6 and B12 were administered together; their individual contributions cannot be separated. exposure: Folic acid 2.5 mg, B6 50 mg and B12 1 mg/day together versus placebo; combined intervention, not isolated folate. cross_nutrient: Directly records the combined B6/B12/folic-acid exposure. [fol-hope2006] Homocysteine lowering with folic acid and B vitamins in vascular disease (2006). https://pubmed.ncbi.nlm.nih.gov/16531613/ DOI: 10.1056/nejmoa060900
    Complete structured claim and evidence

  3. The primary cardiovascular death/MI/stroke composite occurred in 18.8% versus 19.8% (RR 0.95; 95% CI 0.84–1.07), without a significant treatment effect.

    Folic acid → Major cardiovascular event incidence source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years.
    exposure
    Folic acid 2.5 mg, B6 50 mg and B12 1 mg/day together versus placebo; combined intervention, not isolated folate.
    limitations
    Distinct population, regimen and endpoint from CSPPT; this is an outcome boundary, not a contradiction to a biochemical reaction.
    nutrient_topic
    Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
    organism
    Homo sapiens
    plain_language
    Improving homocysteine did not establish benefit for the primary clinical endpoint.
    primary_references
    [fol-hope2006] Homocysteine lowering with folic acid and B vitamins in vascular disease (2006). https://pubmed.ncbi.nlm.nih.gov/16531613/ DOI: 10.1056/nejmoa060900
    tissue_or_cell_type
    Human blood or whole-person clinical endpoints

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1630–1640

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years. · source_derived_draft · unverified_draft

    ### fol-hope2-primary-outcome-null The primary cardiovascular death/MI/stroke composite occurred in 18.8% versus 19.8% (RR 0.95; 95% CI 0.84–1.07), without a significant treatment effect. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: Improving homocysteine did not establish benefit for the primary clinical endpoint. organism: Homo sapiens tissue_or_cell_type: Human blood or whole-person clinical endpoints experimental_model: Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years. limitations: Distinct population, regimen and endpoint from CSPPT; this is an outcome boundary, not a contradiction to a biochemical reaction. exposure: Folic acid 2.5 mg, B6 50 mg and B12 1 mg/day together versus placebo; combined intervention, not isolated folate. [fol-hope2006] Homocysteine lowering with folic acid and B vitamins in vascular disease (2006). https://pubmed.ncbi.nlm.nih.gov/16531613/ DOI: 10.1056/nejmoa060900
    Complete structured claim and evidence

  4. The stroke endpoint was lower with combined vitamins (RR 0.75; 95% CI 0.59–0.97), despite the null primary composite.

    Folic acid → Stroke incidence source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years.
    exposure
    Folic acid 2.5 mg, B6 50 mg and B12 1 mg/day together versus placebo; combined intervention, not isolated folate.
    limitations
    Interpret secondary/component findings alongside the trial hierarchy and the reported increase in unstable-angina hospitalizations; not a general cardiovascular protection claim.
    nutrient_topic
    Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
    organism
    Homo sapiens
    plain_language
    One clinical component improved while the combined primary outcome did not.
    primary_references
    [fol-hope2006] Homocysteine lowering with folic acid and B vitamins in vascular disease (2006). https://pubmed.ncbi.nlm.nih.gov/16531613/ DOI: 10.1056/nejmoa060900
    tissue_or_cell_type
    Human blood or whole-person clinical endpoints

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1642–1652

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years. · source_derived_draft · unverified_draft

    ### fol-hope2-stroke-secondary The stroke endpoint was lower with combined vitamins (RR 0.75; 95% CI 0.59–0.97), despite the null primary composite. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: One clinical component improved while the combined primary outcome did not. organism: Homo sapiens tissue_or_cell_type: Human blood or whole-person clinical endpoints experimental_model: Randomized HOPE-2: 5522 adults at least 55 years old with vascular disease or diabetes, mean five years. limitations: Interpret secondary/component findings alongside the trial hierarchy and the reported increase in unstable-angina hospitalizations; not a general cardiovascular protection claim. exposure: Folic acid 2.5 mg, B6 50 mg and B12 1 mg/day together versus placebo; combined intervention, not isolated folate. [fol-hope2006] Homocysteine lowering with folic acid and B vitamins in vascular disease (2006). https://pubmed.ncbi.nlm.nih.gov/16531613/ DOI: 10.1056/nejmoa060900
    Complete structured claim and evidence

  5. Thirty-five of 66 alcoholic subjects selected for normal liver function and haematology had plasma PLP below 5 ng/ml, the lowest value found in 94 controls.

    Habitual alcohol consumption → Plasma pyridoxal 5-prime-phosphate concentration source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_span
    {"source_cache": "artifacts/alcohol-research/4359937.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08", "start_char": 0, "end_char": 1650, "text_sha256": "1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08"}
    experimental_model
    Plasma PLP in 66 alcoholic subjects without liver abnormality, plus erythrocyte enzyme assays
    exposure
    Chronic alcohol abuse; acetaldehyde and ethanol applied to erythrocytes
    limitations
    Selecting subjects without abnormal liver function isolates the vitamin effect from liver disease. The phosphatase mechanism is shown in erythrocytes, not liver.
    nutrient_topic
    Alcohol research collection; topical membership is not evidence of a direct clinical effect, and ethanol is recorded separately from the acetaldehyde it becomes. · Ethanol
    organism
    Human
    plain_language
    More than half had less of the active vitamin than any healthy control, with healthy livers.
    primary_references
    [alcohol-p4359937] Vitamin B6 metabolism in chronic alcohol abuse. Pyridoxal phosphate levels in plasma and the effects of acetaldehyde on pyridoxal phosphate synthesis and degradation in human erythrocytes. (1974). https://pubmed.ncbi.nlm.nih.gov/4359937/ DOI: 10.1172/jci107607
    tissue_or_cell_type
    Plasma and erythrocytes
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Alcohol: ethanol clearance, acetaldehyde, the channels it binds, organ injury and nutrient collisions (2026-09-21) · lines 631–642

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Plasma PLP in 66 alcoholic subjects without liver abnormality, plus erythrocyte enzyme assays · source_derived_draft · unverified_draft

    ### alcohol-low-plp-prevalence Thirty-five of 66 alcoholic subjects selected for normal liver function and haematology had plasma PLP below 5 ng/ml, the lowest value found in 94 controls. Condition category: nutrient_deficiency nutrient_topic: Alcohol research collection; topical membership is not evidence of a direct clinical effect, and ethanol is recorded separately from the acetaldehyde it becomes. plain_language: More than half had less of the active vitamin than any healthy control, with healthy livers. organism: Human tissue_or_cell_type: Plasma and erythrocytes experimental_model: Plasma PLP in 66 alcoholic subjects without liver abnormality, plus erythrocyte enzyme assays limitations: Selecting subjects without abnormal liver function isolates the vitamin effect from liver disease. The phosphatase mechanism is shown in erythrocytes, not liver. exposure: Chronic alcohol abuse; acetaldehyde and ethanol applied to erythrocytes evidence_span: {"source_cache": "artifacts/alcohol-research/4359937.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08", "start_char": 0, "end_char": 1650, "text_sha256": "1df4485150b1be55f3e5214c424f960ff627cfc317e643c86a0f6747efed8b08"} [alcohol-p4359937] Vitamin B6 metabolism in chronic alcohol abuse. Pyridoxal phosphate levels in plasma and the effects of acetaldehyde on pyridoxal phosphate synthesis and degradation in human erythrocytes. (1974). https://pubmed.ncbi.nlm.nih.gov/4359937/ DOI: 10.1172/jci107607
    Complete structured claim and evidence

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

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