Component

Blood transketolase activity

Measured transketolase activity in blood; not a direct measurement of brain enzyme flux.

5 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. In the 1974 report, blood transketolase recovered more slowly after thiamine in the hypomagnesemic patient than in two normomagnesemic patients.

    Mg2+ → Blood transketolase activity source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    cross_nutrient
    Magnesium availability supports vitamin B1 activation or cofactor use in the specified preparation; this does not establish a dietary threshold or universal treatment failure.
    experimental_model
    Three acute Wernicke-Korsakoff patients: two normomagnesemic and one hypomagnesemic; serial blood transketolase and clinical assessment.
    limitations
    Three patients; blood transketolase is not direct brain flux.
    nutrient_topic
    Magnesium research collection; topical membership is not evidence of a direct dietary effect. · Magnesium
    organism
    Homo sapiens
    plain_language
    Low serum magnesium accompanied a delayed blood-enzyme response to B1.
    primary_references
    [traviesa-1974-thiamine] Magnesium deficiency: a possible cause of thiamine refractoriness in Wernicke-Korsakoff encephalopathy (1974). https://pubmed.ncbi.nlm.nih.gov/4420329/ DOI: 10.1136/jnnp.37.8.959
    tissue_or_cell_type
    Blood; acute Wernicke-Korsakoff patients
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Magnesium: cross-nutrient mechanisms and deficiency (2026-09-17) · lines 735–745

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Three acute Wernicke-Korsakoff patients: two normomagnesemic and one hypomagnesemic; serial blood transketolase and clinical assessment. · source_derived_draft · unverified_draft

    ### mg-thiamine-delayed-blood-tkt In the 1974 report, blood transketolase recovered more slowly after thiamine in the hypomagnesemic patient than in two normomagnesemic patients. Condition category: nutrient_deficiency nutrient_topic: Magnesium research collection; topical membership is not evidence of a direct dietary effect. plain_language: Low serum magnesium accompanied a delayed blood-enzyme response to B1. organism: Homo sapiens tissue_or_cell_type: Blood; acute Wernicke-Korsakoff patients experimental_model: Three acute Wernicke-Korsakoff patients: two normomagnesemic and one hypomagnesemic; serial blood transketolase and clinical assessment. limitations: Three patients; blood transketolase is not direct brain flux. cross_nutrient: Magnesium availability supports vitamin B1 activation or cofactor use in the specified preparation; this does not establish a dietary threshold or universal treatment failure. [traviesa-1974-thiamine] Magnesium deficiency: a possible cause of thiamine refractoriness in Wernicke-Korsakoff encephalopathy (1974). https://pubmed.ncbi.nlm.nih.gov/4420329/ DOI: 10.1136/jnnp.37.8.959
    Complete structured claim and evidence

  2. The trial found no significant between-group effect on its primary endpoint of change in erythrocyte transketolase activity.

    Magnesium sulfate → Blood transketolase activity source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    115 analyzed; biochemical measurement two hours after treatment.
    exposure
    Thiamine 250 mg as Pabrinex, magnesium sulfate 2 g, or both; biochemical samples at two hours. Initial magnesium-only group then received thiamine. Study regimens, not recommendations.
    limitations
    Does not refute molecular Mg requirements or prove no effect in deficient tissues; almost all participants lacked low erythrocyte ThDP.
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Homo sapiens
    plain_language
    The enzyme endpoint did not improve significantly across treatment groups.
    primary_references
    [b1-maguire2022] Randomised trial of intravenous thiamine and/or magnesium sulphate administration on erythrocyte transketolase activity, lactate concentrations and alcohol withdrawal scores (2022). https://pubmed.ncbi.nlm.nih.gov/35484175/ DOI: 10.1038/s41598-022-10970-x
    tissue_or_cell_type
    Erythrocytes

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1599–1609

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · 115 analyzed; biochemical measurement two hours after treatment. · source_derived_draft · unverified_draft

    ### b1-aws-mg-transketolase-null The trial found no significant between-group effect on its primary endpoint of change in erythrocyte transketolase activity. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: The enzyme endpoint did not improve significantly across treatment groups. organism: Homo sapiens tissue_or_cell_type: Erythrocytes experimental_model: 115 analyzed; biochemical measurement two hours after treatment. limitations: Does not refute molecular Mg requirements or prove no effect in deficient tissues; almost all participants lacked low erythrocyte ThDP. exposure: Thiamine 250 mg as Pabrinex, magnesium sulfate 2 g, or both; biochemical samples at two hours. Initial magnesium-only group then received thiamine. Study regimens, not recommendations. [b1-maguire2022] Randomised trial of intravenous thiamine and/or magnesium sulphate administration on erythrocyte transketolase activity, lactate concentrations and alcohol withdrawal scores (2022). https://pubmed.ncbi.nlm.nih.gov/35484175/ DOI: 10.1038/s41598-022-10970-x
    Complete structured claim and evidence

  3. The functional erythrocyte test compared transketolase activity before and after adding exogenous thiamine diphosphate.

    Thiamine diphosphate → Blood transketolase activity source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    biomarker_context Imported condition classification; unverified.
    evidence_location
    Abstract
    evidence_span
    before and after activation with exogenous thiamin diphosphate
    experimental_model
    Human erythrocytes incubated with thiamine, plus alcoholic, elderly and student comparison groups; HPLC ThDP versus basal and ThDP-stimulated transketolase assays.
    exposure
    Laboratory assessment of thiamine status using erythrocytes or whole blood
    limitations
    Assay response is influenced by the enzyme preparation and assay conditions; a small response is not a measurement of every tissue.
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Homo sapiens
    plain_language
    This asks how much extra cofactor can activate the sampled enzyme, whereas HPLC counts the cofactor itself.
    primary_references
    [baines-1988-erythrocyte-assays] The Evaluation of Erythrocyte Thiamin Diphosphate as an Indicator of Thiamin Status in Man, and its Comparison with Erythrocyte Transketolase Activity Measurements (1988). https://journals.sagepub.com/doi/10.1177/000456328802500617 DOI: 10.1177/000456328802500617
    tissue_or_cell_type
    Erythrocyte hemolysates
    trigger_kind
    biomarker_context Imported condition classification; unverified.

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1381–1393

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human erythrocytes incubated with thiamine, plus alcoholic, elderly and student comparison groups; HPLC ThDP versus basal and ThDP-stimulated transketolase assays. · source_derived_draft · unverified_draft

    ### thiamine-def-exogenous-thdp-functional-assay The functional erythrocyte test compared transketolase activity before and after adding exogenous thiamine diphosphate. Condition category: biomarker_context nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: This asks how much extra cofactor can activate the sampled enzyme, whereas HPLC counts the cofactor itself. organism: Homo sapiens tissue_or_cell_type: Erythrocyte hemolysates experimental_model: Human erythrocytes incubated with thiamine, plus alcoholic, elderly and student comparison groups; HPLC ThDP versus basal and ThDP-stimulated transketolase assays. limitations: Assay response is influenced by the enzyme preparation and assay conditions; a small response is not a measurement of every tissue. evidence_location: Abstract evidence_span: before and after activation with exogenous thiamin diphosphate exposure: Laboratory assessment of thiamine status using erythrocytes or whole blood [baines-1988-erythrocyte-assays] The Evaluation of Erythrocyte Thiamin Diphosphate as an Indicator of Thiamin Status in Man, and its Comparison with Erythrocyte Transketolase Activity Measurements (1988). https://journals.sagepub.com/doi/10.1177/000456328802500617 DOI: 10.1177/000456328802500617
    Complete structured claim and evidence

  4. Direct erythrocyte ThDP was more stable during frozen storage than transketolase activity in the evaluated preparations.

    Erythrocyte thiamine diphosphate concentration → Blood transketolase activity source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    biomarker_context Imported condition classification; unverified.
    evidence_location
    Abstract
    evidence_span
    ETDP is more stable than ETKA in frozen erythrocytes
    experimental_model
    Human erythrocytes incubated with thiamine, plus alcoholic, elderly and student comparison groups; HPLC ThDP versus basal and ThDP-stimulated transketolase assays.
    exposure
    Laboratory assessment of thiamine status using erythrocytes or whole blood
    limitations
    Historical assay comparison, not a validated stability duration for every modern collection tube or analytical platform.
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Homo sapiens
    plain_language
    Storage can affect the chemical measurement and the functional enzyme test differently.
    primary_references
    [baines-1988-erythrocyte-assays] The Evaluation of Erythrocyte Thiamin Diphosphate as an Indicator of Thiamin Status in Man, and its Comparison with Erythrocyte Transketolase Activity Measurements (1988). https://journals.sagepub.com/doi/10.1177/000456328802500617 DOI: 10.1177/000456328802500617
    tissue_or_cell_type
    Frozen erythrocyte specimens
    trigger_kind
    biomarker_context Imported condition classification; unverified.

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1395–1407

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human erythrocytes incubated with thiamine, plus alcoholic, elderly and student comparison groups; HPLC ThDP versus basal and ThDP-stimulated transketolase assays. · source_derived_draft · unverified_draft

    ### thiamine-def-frozen-erythrocyte-stability Direct erythrocyte ThDP was more stable during frozen storage than transketolase activity in the evaluated preparations. Condition category: biomarker_context nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Storage can affect the chemical measurement and the functional enzyme test differently. organism: Homo sapiens tissue_or_cell_type: Frozen erythrocyte specimens experimental_model: Human erythrocytes incubated with thiamine, plus alcoholic, elderly and student comparison groups; HPLC ThDP versus basal and ThDP-stimulated transketolase assays. limitations: Historical assay comparison, not a validated stability duration for every modern collection tube or analytical platform. evidence_location: Abstract evidence_span: ETDP is more stable than ETKA in frozen erythrocytes exposure: Laboratory assessment of thiamine status using erythrocytes or whole blood [baines-1988-erythrocyte-assays] The Evaluation of Erythrocyte Thiamin Diphosphate as an Indicator of Thiamin Status in Man, and its Comparison with Erythrocyte Transketolase Activity Measurements (1988). https://journals.sagepub.com/doi/10.1177/000456328802500617 DOI: 10.1177/000456328802500617
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. The index infant had nystagmus, ophthalmoplegia, elevated lactate and abnormal transketolase activation despite normal brain MRI.

    Thiamine (vitamin B1) → Wernicke encephalopathy neurological symptoms source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    evidence_location
    Results: Patient 1
    evidence_span
    Brain magnetic resonance imaging (MRI) revealed no abnormalities
    experimental_model
    Nine Israeli infants aged 2-12 months exposed to a defective soy-based formula in the 2003 outbreak; clinical examination, erythrocyte transketolase activation, lactate and selected neuroimaging.
    exposure
    Consumption of a formula with thiamine below the assay detection limit
    limitations
    Single-patient diagnostic boundary; does not estimate MRI sensitivity or make every neurological symptom a thiamine-deficiency manifestation.
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Homo sapiens
    plain_language
    Normal structural imaging did not exclude clinically important deficiency in this infant.
    primary_references
    [fattal-valevski-2005-formula-outbreak] Outbreak of life-threatening thiamine deficiency in infants in Israel caused by a defective soy-based formula. (2005). https://pubmed.ncbi.nlm.nih.gov/15687431/ DOI: 10.1542/peds.2004-1255
    tissue_or_cell_type
    Neurological examination and brain MRI
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1493–1505

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Nine Israeli infants aged 2-12 months exposed to a defective soy-based formula in the 2003 outbreak; clinical examination, erythrocyte transketolase activation, lactate and selected neuroimaging. · source_derived_draft · unverified_draft

    ### thiamine-def-infant-normal-mri-boundary The index infant had nystagmus, ophthalmoplegia, elevated lactate and abnormal transketolase activation despite normal brain MRI. Condition category: nutrient_deficiency nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Normal structural imaging did not exclude clinically important deficiency in this infant. organism: Homo sapiens tissue_or_cell_type: Neurological examination and brain MRI experimental_model: Nine Israeli infants aged 2-12 months exposed to a defective soy-based formula in the 2003 outbreak; clinical examination, erythrocyte transketolase activation, lactate and selected neuroimaging. limitations: Single-patient diagnostic boundary; does not estimate MRI sensitivity or make every neurological symptom a thiamine-deficiency manifestation. evidence_location: Results: Patient 1 evidence_span: Brain magnetic resonance imaging (MRI) revealed no abnormalities exposure: Consumption of a formula with thiamine below the assay detection limit [fattal-valevski-2005-formula-outbreak] Outbreak of life-threatening thiamine deficiency in infants in Israel caused by a defective soy-based formula. (2005). https://pubmed.ncbi.nlm.nih.gov/15687431/ DOI: 10.1542/peds.2004-1255
    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.

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