Component

B12-associated neuropsychiatric impairment

Independent substance, clinical endpoint or measured readout; study context is retained with each finding.

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. Of 141 neurologic B12-deficiency patients, 34 had normal hematocrit, 25 normal mean cell volume, and 19 both; 40 lacked at least one of these two abnormalities.

    Vitamin B12 (cobalamins) → B12-associated neuropsychiatric impairment source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    nutrient_deficiency Imported condition classification; unverified.
    experimental_model
    Clinical series: 141 consecutive patients with neuropsychiatric abnormalities attributed to cobalamin deficiency; 40 lacked anemia or macrocytosis.
    exposure
    Clinical evaluation and cobalamin replacement; observational response series.
    limitations
    The reported 28% is not the percentage with both tests normal. Selected patients do not estimate population prevalence.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Normal red-cell size or hematocrit did not exclude the neurologic presentation.
    primary_references
    [b12-lindenbaum1988] Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis (1988). https://pubmed.ncbi.nlm.nih.gov/3374544/ DOI: 10.1056/nejm198806303182604
    tissue_or_cell_type
    Human blood or whole-person endpoints
    trigger_kind
    nutrient_deficiency Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1426–1436

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Clinical series: 141 consecutive patients with neuropsychiatric abnormalities attributed to cobalamin deficiency; 40 lacked anemia or macrocytosis. · source_derived_draft · unverified_draft

    ### b12-neuro-normal-blood-counts Of 141 neurologic B12-deficiency patients, 34 had normal hematocrit, 25 normal mean cell volume, and 19 both; 40 lacked at least one of these two abnormalities. Condition category: nutrient_deficiency nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Normal red-cell size or hematocrit did not exclude the neurologic presentation. organism: Homo sapiens tissue_or_cell_type: Human blood or whole-person endpoints experimental_model: Clinical series: 141 consecutive patients with neuropsychiatric abnormalities attributed to cobalamin deficiency; 40 lacked anemia or macrocytosis. limitations: The reported 28% is not the percentage with both tests normal. Selected patients do not estimate population prevalence. exposure: Clinical evaluation and cobalamin replacement; observational response series. [b12-lindenbaum1988] Neuropsychiatric disorders caused by cobalamin deficiency in the absence of anemia or macrocytosis (1988). https://pubmed.ncbi.nlm.nih.gov/3374544/ DOI: 10.1056/nejm198806303182604
    Complete structured claim and evidence

  2. Twelve of 419 recognized B12-deficient patients had serum cobalamin above 200 pg/mL; five had prominent neurologic involvement that responded to therapy.

    Serum cobalamin concentration → B12-associated neuropsychiatric impairment source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    biomarker_context Imported condition classification; unverified.
    experimental_model
    Maintenance-relapse observations plus a review of 419 recognized B12-deficient patients.
    exposure
    Serum cobalamin, MMA and total homocysteine measurements; clinical response used in diagnosis.
    limitations
    Retrospective diagnostic attribution; no estimate of specificity in unselected patients. Potential cohort overlap with related reports.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    A single circulating B12 measurement is not a complete picture of function.
    primary_references
    [b12-lindenbaum1990] Diagnosis of cobalamin deficiency: II. Relative sensitivities of serum cobalamin, methylmalonic acid, and total homocysteine concentrations (1990). https://pubmed.ncbi.nlm.nih.gov/2339684/ DOI: 10.1002/ajh.2830340205
    tissue_or_cell_type
    Human blood or whole-person endpoints
    trigger_kind
    biomarker_context Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1500–1510

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Maintenance-relapse observations plus a review of 419 recognized B12-deficient patients. · source_derived_draft · unverified_draft

    ### b12-serum-normal-recognized-cases Twelve of 419 recognized B12-deficient patients had serum cobalamin above 200 pg/mL; five had prominent neurologic involvement that responded to therapy. Condition category: biomarker_context nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A single circulating B12 measurement is not a complete picture of function. organism: Homo sapiens tissue_or_cell_type: Human blood or whole-person endpoints experimental_model: Maintenance-relapse observations plus a review of 419 recognized B12-deficient patients. limitations: Retrospective diagnostic attribution; no estimate of specificity in unselected patients. Potential cohort overlap with related reports. exposure: Serum cobalamin, MMA and total homocysteine measurements; clinical response used in diagnosis. [b12-lindenbaum1990] Diagnosis of cobalamin deficiency: II. Relative sensitivities of serum cobalamin, methylmalonic acid, and total homocysteine concentrations (1990). https://pubmed.ncbi.nlm.nih.gov/2339684/ DOI: 10.1002/ajh.2830340205
    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