{"id":"70f004a3-f072-5c4b-b7c8-78720ea6abdd","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:c-whole-diet-iron-absorption-null","predicate":"whole_diet_variation_did_not_significantly_change_mean_iron_absorption","statement":"Mean iron absorption did not differ significantly across the three complete-diet periods despite mean vitamin C intakes spanning 51–247 mg/day.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"d957b5e0-09a0-5ae3-8df9-78d0d633088b","mechanism_event_label":"An effect visible in a single meal can be much smaller across a complete diet.","subject":{"id":"2047867f-9872-53b2-a553-71c911d0695b","slug":"ascorbic-acid","display_name":"L-Ascorbic acid","entity_type_key":"small_molecule"},"object":{"id":"4429d8ae-d732-5f5e-acc1-2c872e23da62","slug":"nonheme-iron-absorption","display_name":"Nonheme iron absorption","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"d957b5e0-09a0-5ae3-8df9-78d0d633088b","stable_key":"cb568d28-484a-5c2e-9fcc-2d780358e514:c-whole-diet-iron-absorption-null-event","event_type":"observed_intervention","label":"An effect visible in a single meal can be much smaller across a complete diet.","description":"Mean iron absorption did not differ significantly across the three complete-diet periods despite mean vitamin C intakes spanning 51–247 mg/day.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"role":"affected_nutrient","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":"4429d8ae-d732-5f5e-acc1-2c872e23da62","slug":"nonheme-iron-absorption","display_name":"Nonheme iron absorption","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Human total-diet boundary on the single-meal interaction.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Twelve subjects completing three dietary periods; labeled wheat rolls with every meal for five days per period.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Self-selected, low-C and high-C complete diets; mean vitamin C intakes spanned 51–247 mg/day.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Only twelve participants; meals and iron status also varied. Different design from the phytate challenge, not a draft correction or an unexplained contradiction.","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":"An effect visible in a single meal can be much smaller across a complete diet.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[c-cook2001] Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet (2001). https://pubmed.ncbi.nlm.nih.gov/11124756/ DOI: 10.1093/ajcn/73.1.93","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":"23981f4a-5394-525c-a8f8-a28b1ebd0999","evidence_kind":"source_excerpt","locator":"Lines 1593-1604","start_line":1593,"end_line":1604,"excerpt":"### c-whole-diet-iron-absorption-null\nMean iron absorption did not differ significantly across the three complete-diet periods despite mean vitamin C intakes spanning 51–247 mg/day.\nCondition category: normal\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: An effect visible in a single meal can be much smaller across a complete diet.\norganism: Homo sapiens\ntissue_or_cell_type: Human blood or whole-person endpoints\nexperimental_model: Twelve subjects completing three dietary periods; labeled wheat rolls with every meal for five days per period.\nlimitations: Only twelve participants; meals and iron status also varied. Different design from the phytate challenge, not a draft correction or an unexplained contradiction.\nexposure: Self-selected, low-C and high-C complete diets; mean vitamin C intakes spanned 51–247 mg/day.\ncross_nutrient: Human total-diet boundary on the single-meal interaction.\n[c-cook2001] Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet (2001). https://pubmed.ncbi.nlm.nih.gov/11124756/ DOI: 10.1093/ajcn/73.1.93","model_system":"Twelve subjects completing three dietary periods; labeled wheat rolls with every meal for five days per period.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [c-cook2001] Effect of ascorbic acid intake on nonheme-iron absorption from a complete diet (2001). https://pubmed.ncbi.nlm.nih.gov/11124756/ DOI: 10.1093/ajcn/73.1.93","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"fa811221-13bd-5c10-adc1-eaf097c7703c","stable_key":"import-cb568d28-484a-5c2e-9fcc-2d780358e514","title":"Vitamin C: 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":"b7fd83f956abb81855f2ea23199ba14e465cd91f4a2ac560277ec21ddafd7bfc","revision_id":"6cde9bbb-d712-5746-82a6-85b144253efa","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}