Component

Neural-tube defect incidence

Independently recorded substance, clinical endpoint or assay readout. Claims retain study-specific population and measurement context.

4 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. Among women registered before the last menstrual period, NTD rates with periconceptional folic acid use versus no use were 1.0 versus 4.8 per 1000 in northern China and 0.6 versus 1.0 per 1000 in southern China; denominators were pregnancies of at least 20 weeks gestation.

    Folic acid → Neural-tube defect incidence source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Prospective nonrandomized community intervention in northern and southern China, 1993–1995.
    exposure
    400 micrograms/day folic acid alone from premarital examination through first trimester; actual use and adherence recorded.
    limitations
    Nonrandomized adherence and use can be confounded. Regional effect sizes do not define a universal biological response.
    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 observed benefit appeared in regions with different starting risks.
    primary_references
    [fol-berry1999] Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention (1999). https://pubmed.ncbi.nlm.nih.gov/10559448/ DOI: 10.1056/nejm199911113412001
    tissue_or_cell_type
    Community pregnancy outcomes

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1384–1394

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Prospective nonrandomized community intervention in northern and southern China, 1993–1995. · source_derived_draft · unverified_draft

    ### fol-china-periconception-ntd Among women registered before the last menstrual period, NTD rates with periconceptional folic acid use versus no use were 1.0 versus 4.8 per 1000 in northern China and 0.6 versus 1.0 per 1000 in southern China; denominators were pregnancies of at least 20 weeks gestation. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: The observed benefit appeared in regions with different starting risks. organism: Homo sapiens tissue_or_cell_type: Community pregnancy outcomes experimental_model: Prospective nonrandomized community intervention in northern and southern China, 1993–1995. limitations: Nonrandomized adherence and use can be confounded. Regional effect sizes do not define a universal biological response. exposure: 400 micrograms/day folic acid alone from premarital examination through first trimester; actual use and adherence recorded. [fol-berry1999] Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention (1999). https://pubmed.ncbi.nlm.nih.gov/10559448/ DOI: 10.1056/nejm199911113412001
    Complete structured claim and evidence

  2. The Hungarian trial observed zero NTDs among 2104 known-outcome multivitamin pregnancies and six among 2052 trace-element pregnancies (P=0.029).

    Folic acid → Neural-tube defect incidence source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Cointervention with multiple vitamins and minerals is retained explicitly.
    experimental_model
    Randomized Hungarian first-occurrence prevention trial; known outcomes in 2104 multivitamin and 2052 trace-element recipients.
    exposure
    Multivitamin including 0.8 mg folic acid versus trace elements with low vitamin C; at least one month before conception through second missed period or later.
    limitations
    The randomized comparison cannot assign its entire effect to folic acid alone or demonstrate equivalence of other folate formulations.
    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 supplement containing folic acid reduced first occurrences, but it also contained other vitamins and minerals.
    primary_references
    [fol-czeizel1992] Prevention of the first occurrence of neural-tube defects by periconceptional vitamin supplementation (1992). https://pubmed.ncbi.nlm.nih.gov/1307234/ DOI: 10.1056/nejm199212243272602
    tissue_or_cell_type
    Pregnancy and fetal developmental outcomes

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1371–1382

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized Hungarian first-occurrence prevention trial; known outcomes in 2104 multivitamin and 2052 trace-element recipients. · source_derived_draft · unverified_draft

    ### fol-ntd-first-occurrence-multivitamin The Hungarian trial observed zero NTDs among 2104 known-outcome multivitamin pregnancies and six among 2052 trace-element pregnancies (P=0.029). Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: The supplement containing folic acid reduced first occurrences, but it also contained other vitamins and minerals. organism: Homo sapiens tissue_or_cell_type: Pregnancy and fetal developmental outcomes experimental_model: Randomized Hungarian first-occurrence prevention trial; known outcomes in 2104 multivitamin and 2052 trace-element recipients. limitations: The randomized comparison cannot assign its entire effect to folic acid alone or demonstrate equivalence of other folate formulations. exposure: Multivitamin including 0.8 mg folic acid versus trace elements with low vitamin C; at least one month before conception through second missed period or later. cross_nutrient: Cointervention with multiple vitamins and minerals is retained explicitly. [fol-czeizel1992] Prevention of the first occurrence of neural-tube defects by periconceptional vitamin supplementation (1992). https://pubmed.ncbi.nlm.nih.gov/1307234/ DOI: 10.1056/nejm199212243272602
    Complete structured claim and evidence

  3. The MRC trial recorded 6 NTD-affected pregnancies in folic-acid groups and 21 in groups without folic acid: relative risk 0.28 (95% CI 0.12–0.71).

    Folic acid → Neural-tube defect incidence source_derived_draftungraded
    Experimental context and source evidence
    experimental_model
    Randomized double-blind factorial trial at 33 centers in seven countries; 1817 women with a previous NTD-affected pregnancy, 1195 informative pregnancies.
    exposure
    Folic acid 4 mg/day, seven other vitamins, both or neither from randomization to 12 weeks of pregnancy. Historical trial exposure.
    limitations
    Not every NTD was prevented. Early stopping can inflate an effect estimate; the report also supplied an adjusted estimate. The trial did not isolate a cellular mechanism.
    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
    Adding folic acid before and early in pregnancy prevented many recurrences in this high-risk trial.
    primary_references
    [fol-mrc1991] Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group (1991). https://pubmed.ncbi.nlm.nih.gov/1677062/ DOI: 10.1016/0140-6736(91)90133-A
    tissue_or_cell_type
    Pregnancy and fetal developmental outcomes

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1359–1369

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Randomized double-blind factorial trial at 33 centers in seven countries; 1817 women with a previous NTD-affected pregnancy, 1195 informative pregnancies. · source_derived_draft · unverified_draft

    ### fol-ntd-recurrence-randomized The MRC trial recorded 6 NTD-affected pregnancies in folic-acid groups and 21 in groups without folic acid: relative risk 0.28 (95% CI 0.12–0.71). Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: Adding folic acid before and early in pregnancy prevented many recurrences in this high-risk trial. organism: Homo sapiens tissue_or_cell_type: Pregnancy and fetal developmental outcomes experimental_model: Randomized double-blind factorial trial at 33 centers in seven countries; 1817 women with a previous NTD-affected pregnancy, 1195 informative pregnancies. limitations: Not every NTD was prevented. Early stopping can inflate an effect estimate; the report also supplied an adjusted estimate. The trial did not isolate a cellular mechanism. exposure: Folic acid 4 mg/day, seven other vitamins, both or neither from randomization to 12 weeks of pregnancy. Historical trial exposure. [fol-mrc1991] Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research Group (1991). https://pubmed.ncbi.nlm.nih.gov/1677062/ DOI: 10.1016/0140-6736(91)90133-A
    Complete structured claim and evidence

  4. The Bayesian model estimated 25.4 NTDs per 10000 births at RBC folate 500 nmol/L, with risk substantially lower above approximately 1000 nmol/L; this was an estimated population relation.

    Erythrocyte folate concentration → Neural-tube defect incidence source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    biomarker_context Imported condition classification; unverified.
    experimental_model
    Bayesian model combining the Chinese prevention cohort (247831 participants) and a separate blood-response trial (1194 women).
    exposure
    Estimated RBC folate at neural-tube closure; modeled population risk, not a prospective test of an individual threshold.
    limitations
    Estimated concentration at neural-tube closure, assay context and model assumptions matter. Reuses the Chinese intervention cohort; not an independent prevention trial.
    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
    Red-cell folate helped model population risk; it was not a pass/fail test for an individual pregnancy.
    primary_references
    [fol-crider2014] Population red blood cell folate concentrations for prevention of neural tube defects: Bayesian model (2014). https://pubmed.ncbi.nlm.nih.gov/25073783/ DOI: 10.1136/bmj.g4554
    tissue_or_cell_type
    Human blood or whole-person clinical endpoints
    trigger_kind
    biomarker_context Imported condition classification; unverified.

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1396–1406

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Bayesian model combining the Chinese prevention cohort (247831 participants) and a separate blood-response trial (1194 women). · source_derived_draft · unverified_draft

    ### fol-rbc-population-risk-model The Bayesian model estimated 25.4 NTDs per 10000 births at RBC folate 500 nmol/L, with risk substantially lower above approximately 1000 nmol/L; this was an estimated population relation. Condition category: biomarker_context nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: Red-cell folate helped model population risk; it was not a pass/fail test for an individual pregnancy. organism: Homo sapiens tissue_or_cell_type: Human blood or whole-person clinical endpoints experimental_model: Bayesian model combining the Chinese prevention cohort (247831 participants) and a separate blood-response trial (1194 women). limitations: Estimated concentration at neural-tube closure, assay context and model assumptions matter. Reuses the Chinese intervention cohort; not an independent prevention trial. exposure: Estimated RBC folate at neural-tube closure; modeled population risk, not a prospective test of an individual threshold. [fol-crider2014] Population red blood cell folate concentrations for prevention of neural tube defects: Bayesian model (2014). https://pubmed.ncbi.nlm.nih.gov/25073783/ DOI: 10.1136/bmj.g4554
    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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