{"id":"fdca426c-b475-5ad1-8b14-686f94dae339","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:fol-china-periconception-ntd","predicate":"use_associated_with_lower_ntd_rates","statement":"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.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"56f37a7b-4f17-5bf4-bc68-dfa7649001fd","mechanism_event_label":"The observed benefit appeared in regions with different starting risks.","subject":{"id":"d322bfef-5135-599f-82e6-0aa58748dc8b","slug":"folic-acid","display_name":"Folic acid","entity_type_key":"small_molecule"},"object":{"id":"763ed160-e614-5def-8cbe-16ecb2e2d003","slug":"neural-tube-defect-incidence","display_name":"Neural-tube defect incidence","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"56f37a7b-4f17-5bf4-bc68-dfa7649001fd","stable_key":"ec174d5a-4903-5745-8646-df0e9d4265e8:fol-china-periconception-ntd-event","event_type":"observed_intervention","label":"The observed benefit appeared in regions with different starting risks.","description":"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.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"d322bfef-5135-599f-82e6-0aa58748dc8b","slug":"folic-acid","display_name":"Folic acid","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"763ed160-e614-5def-8cbe-16ecb2e2d003","slug":"neural-tube-defect-incidence","display_name":"Neural-tube defect incidence","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Prospective nonrandomized community intervention in northern and southern China, 1993–1995.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"400 micrograms/day folic acid alone from premarital examination through first trimester; actual use and adherence recorded.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Nonrandomized adherence and use can be confounded. Regional effect sizes do not define a universal biological response.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"folate","display_name":"Folate (vitamin B9)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The observed benefit appeared in regions with different starting risks.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[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","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Community pregnancy outcomes","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"42fce93a-d6aa-5973-9f0e-0c8510c6976d","evidence_kind":"source_excerpt","locator":"Lines 1384-1394","start_line":1384,"end_line":1394,"excerpt":"### fol-china-periconception-ntd\nAmong 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.\nCondition category: normal\nnutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The observed benefit appeared in regions with different starting risks.\norganism: Homo sapiens\ntissue_or_cell_type: Community pregnancy outcomes\nexperimental_model: Prospective nonrandomized community intervention in northern and southern China, 1993–1995.\nlimitations: Nonrandomized adherence and use can be confounded. Regional effect sizes do not define a universal biological response.\nexposure: 400 micrograms/day folic acid alone from premarital examination through first trimester; actual use and adherence recorded.\n[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","model_system":"Prospective nonrandomized community intervention in northern and southern China, 1993–1995.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study 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","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"f4ce1a62-9582-5f7a-84f5-a23d0e1bfc68","stable_key":"import-ec174d5a-4903-5745-8646-df0e9d4265e8","title":"Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"e564d43989ece1006c95cd0748e9af6fe369074599a2eebba0a99ebff864b0dd","revision_id":"76674a33-b2a1-5e41-b71b-44399038ff7c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}