{"id":"d5564d6a-58dc-5d3c-aae2-25710f457c86","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:c-high-oral-dose-oxalate-synthesis","predicate":"increases_estimated_endogenous_oxalate_in_responders","statement":"Within the responder subset, estimated endogenous oxalate synthesis was 544 versus 391 micromol/day with versus without supplementation.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"d6a5dd72-4dd8-5282-aca1-f3aa5afc22e0","mechanism_event_label":"The tracer-based analysis separated oxalate made within the body from oxalate absorbed from the test diet.","subject":{"id":"2047867f-9872-53b2-a553-71c911d0695b","slug":"ascorbic-acid","display_name":"L-Ascorbic acid","entity_type_key":"small_molecule"},"object":{"id":"5a80e2d1-bdd6-5132-8921-df651b36cb27","slug":"endogenous-oxalate-synthesis","display_name":"Endogenous oxalate synthesis","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"d6a5dd72-4dd8-5282-aca1-f3aa5afc22e0","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:c-high-oral-dose-oxalate-synthesis-event","event_type":"observed_intervention","label":"The tracer-based analysis separated oxalate made within the body from oxalate absorbed from the test diet.","description":"Within the responder subset, estimated endogenous oxalate synthesis was 544 versus 391 micromol/day with versus without supplementation.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"9c8d2b72-517d-5bb6-8589-cabd98267f65","slug":"oxalate","display_name":"Oxalate","entity_type_key":"ion"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"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":1,"notes":""},{"entity":{"id":"5a80e2d1-bdd6-5132-8921-df651b36cb27","slug":"endogenous-oxalate-synthesis","display_name":"Endogenous oxalate synthesis","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Randomized controlled-diet crossover study: 29 calcium stone formers and 19 non-stone formers.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Ascorbic acid 1000 mg twice daily for six days versus no supplement for six days; 13C2 oxalate challenge after adaptation.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Selected subgroup and short exposure; does not identify every enzymatic or nonenzymatic conversion step.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin C research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-c","display_name":"Vitamin C","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The tracer-based analysis separated oxalate made within the body from oxalate absorbed from the test diet.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[c-massey2005] Ascorbate increases human oxaluria and kidney stone risk (2005). https://pubmed.ncbi.nlm.nih.gov/15987848/ DOI: 10.1093/jn/135.7.1673","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Human blood or whole-person endpoints","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"fba8408c-43b4-52d2-91a1-08eddd7536c0","evidence_kind":"source_excerpt","locator":"Lines 1658-1668","start_line":1658,"end_line":1668,"excerpt":"### c-high-oral-dose-oxalate-synthesis\nWithin the responder subset, estimated endogenous oxalate synthesis was 544 versus 391 micromol/day with versus without supplementation.\nCondition category: normal\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The tracer-based analysis separated oxalate made within the body from oxalate absorbed from the test diet.\norganism: Homo sapiens\ntissue_or_cell_type: Human blood or whole-person endpoints\nexperimental_model: Randomized controlled-diet crossover study: 29 calcium stone formers and 19 non-stone formers.\nlimitations: Selected subgroup and short exposure; does not identify every enzymatic or nonenzymatic conversion step.\nexposure: Ascorbic acid 1000 mg twice daily for six days versus no supplement for six days; 13C2 oxalate challenge after adaptation.\n[c-massey2005] Ascorbate increases human oxaluria and kidney stone risk (2005). https://pubmed.ncbi.nlm.nih.gov/15987848/ DOI: 10.1093/jn/135.7.1673","model_system":"Randomized controlled-diet crossover study: 29 calcium stone formers and 19 non-stone formers.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. 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