{"id":"39d4e036-382d-577b-b59e-875aa1486932","stable_key":"0ad8610d-d575-5870-b7cd-763a9f750783:copper-ascorbate-cp-oxidase","predicate":"reduces_measured","statement":"The 605 mg/day vitamin C period reduced ceruloplasmin oxidase activity by about 21% in the controlled feeding study.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"3937a19e-c0db-53c0-bb06-a801d1a660fc","mechanism_event_label":"A copper-related enzyme measurement changed with vitamin C intake.","subject":{"id":"2047867f-9872-53b2-a553-71c911d0695b","slug":"ascorbic-acid","display_name":"L-Ascorbic acid","entity_type_key":"small_molecule"},"object":{"id":"ef7ac2c4-5d73-5c0a-809b-222a568c312a","slug":"ceruloplasmin-oxidase-activity","display_name":"Circulating ceruloplasmin oxidase activity","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"3937a19e-c0db-53c0-bb06-a801d1a660fc","stable_key":"0ad8610d-d575-5870-b7cd-763a9f750783:copper-ascorbate-cp-oxidase-event","event_type":"observed_intervention","label":"A copper-related enzyme measurement changed with vitamin C intake.","description":"The 605 mg/day vitamin C period reduced ceruloplasmin oxidase activity by about 21% in the controlled feeding study.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"2047867f-9872-53b2-a553-71c911d0695b","slug":"ascorbic-acid","display_name":"L-Ascorbic acid","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"ef7ac2c4-5d73-5c0a-809b-222a568c312a","slug":"ceruloplasmin-oxidase-activity","display_name":"Circulating ceruloplasmin oxidase activity","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"biomarker_context","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/copper-research/3694287.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"37e70fcbc672023cd6c3616b4a1171c6ded4caafe4e3c14d4f80c6abca490e68\", \"start_char\": 0, \"end_char\": 1031, \"text_sha256\": \"37e70fcbc672023cd6c3616b4a1171c6ded4caafe4e3c14d4f80c6abca490e68\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Controlled sequential dietary vitamin C intervention","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Fourteen-week feeding study: 65, 5, 605 and 5 mg vitamin C/day in successive periods","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Short sequential study; ceruloplasmin activity differs from protein concentration and whole-body copper stores. No universal vitamin C threshold is established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Copper research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"copper","display_name":"Copper","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Human men","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"A copper-related enzyme measurement changed with vitamin C intake.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[copper-p3694287] Effect of varying ascorbic acid intakes on copper absorption and ceruloplasmin levels of young men. (1987). https://pubmed.ncbi.nlm.nih.gov/3694287/ DOI: 10.1093/jn/117.12.2109","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Copper absorption, retention and circulating markers","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"biomarker_context","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"3c8229ed-3001-533c-ac34-2148c8e57ca8","evidence_kind":"source_excerpt","locator":"Lines 1105-1116","start_line":1105,"end_line":1116,"excerpt":"### copper-ascorbate-cp-oxidase\nThe 605 mg/day vitamin C period reduced ceruloplasmin oxidase activity by about 21% in the controlled feeding study.\nCondition category: biomarker_context\nnutrient_topic: Copper research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: A copper-related enzyme measurement changed with vitamin C intake.\norganism: Human men\ntissue_or_cell_type: Copper absorption, retention and circulating markers\nexperimental_model: Controlled sequential dietary vitamin C intervention\nlimitations: Short sequential study; ceruloplasmin activity differs from protein concentration and whole-body copper stores. No universal vitamin C threshold is established.\nexposure: Fourteen-week feeding study: 65, 5, 605 and 5 mg vitamin C/day in successive periods\nevidence_span: {\"source_cache\": \"artifacts/copper-research/3694287.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"37e70fcbc672023cd6c3616b4a1171c6ded4caafe4e3c14d4f80c6abca490e68\", \"start_char\": 0, \"end_char\": 1031, \"text_sha256\": \"37e70fcbc672023cd6c3616b4a1171c6ded4caafe4e3c14d4f80c6abca490e68\"}\n[copper-p3694287] Effect of varying ascorbic acid intakes on copper absorption and ceruloplasmin levels of young men. (1987). https://pubmed.ncbi.nlm.nih.gov/3694287/ DOI: 10.1093/jn/117.12.2109","model_system":"Controlled sequential dietary vitamin C intervention","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [copper-p3694287] Effect of varying ascorbic acid intakes on copper absorption and ceruloplasmin levels of young men. (1987). https://pubmed.ncbi.nlm.nih.gov/3694287/ DOI: 10.1093/jn/117.12.2109","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"9afba495-cbdc-51aa-998e-70a930dba3be","stable_key":"import-0ad8610d-d575-5870-b7cd-763a9f750783","title":"Copper: transport, cuproenzymes, deficiency, excess 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":"84b0f62b2dae6835fa26902be87625c003c6c707492d3007e8f9d15420669008","revision_id":"d7e35b8b-3f77-56d9-90b5-5f542c63f321","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}