{"id":"f62e3a75-c171-5536-ac64-8de77313480a","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-ribofem-absorption","predicate":"did_not_detectably_change_iron_absorption","statement":"RIBOFEM found no change in dietary iron intake or measured iron absorption during the riboflavin intervention.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"7f951e4d-1e6e-535e-bf2d-7f64ba86dd53","mechanism_event_label":"The blood response could not simply be explained by absorbing more iron in the measured subgroup.","subject":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","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":"7f951e4d-1e6e-535e-bf2d-7f64ba86dd53","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-ribofem-absorption-event","event_type":"observed_intervention","label":"The blood response could not simply be explained by absorbing more iron in the measured subgroup.","description":"RIBOFEM found no change in dietary iron intake or measured iron absorption during the riboflavin intervention.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"89bcaf42-b4ab-5760-8c2e-44eace10cee0","slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"},"role":"measured_nutrient","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","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":"availability_state","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"cross_nutrient","value_text":"Iron absorption and iron use remain separate entities.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"RIBOFEM: 123 UK women aged 19-25 randomized with EGRAC >1.40; 119 completed, 117 analyzed after two exclusions; iron-absorption subset 34.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Placebo, 2 or 4 mg/day riboflavin for eight weeks; historical trial regimens.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Small absorption subgroup; no measured change is not proof of identical absorption in all settings. Actual downstream causal step remains unresolved.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Riboflavin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The blood response could not simply be explained by absorbing more iron in the measured subgroup.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b2-powers2011] Correcting a marginal riboflavin deficiency improves hematologic status in young women in the United Kingdom (RIBOFEM) (2011). https://pubmed.ncbi.nlm.nih.gov/21525198/ DOI: 10.3945/ajcn.110.008409","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Human clinical setting","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"cf16a649-55ce-52fe-9b24-805e5411f6d1","evidence_kind":"source_excerpt","locator":"Lines 1565-1576","start_line":1565,"end_line":1576,"excerpt":"### b2-ribofem-absorption\nRIBOFEM found no change in dietary iron intake or measured iron absorption during the riboflavin intervention.\nCondition category: nutrient_deficiency\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The blood response could not simply be explained by absorbing more iron in the measured subgroup.\norganism: Homo sapiens\ntissue_or_cell_type: Human clinical setting\nexperimental_model: RIBOFEM: 123 UK women aged 19-25 randomized with EGRAC >1.40; 119 completed, 117 analyzed after two exclusions; iron-absorption subset 34.\nlimitations: Small absorption subgroup; no measured change is not proof of identical absorption in all settings. Actual downstream causal step remains unresolved.\nexposure: Placebo, 2 or 4 mg/day riboflavin for eight weeks; historical trial regimens.\ncross_nutrient: Iron absorption and iron use remain separate entities.\n[b2-powers2011] Correcting a marginal riboflavin deficiency improves hematologic status in young women in the United Kingdom (RIBOFEM) (2011). https://pubmed.ncbi.nlm.nih.gov/21525198/ DOI: 10.3945/ajcn.110.008409","model_system":"RIBOFEM: 123 UK women aged 19-25 randomized with EGRAC >1.40; 119 completed, 117 analyzed after two exclusions; iron-absorption subset 34.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b2-powers2011] Correcting a marginal riboflavin deficiency improves hematologic status in young women in the United Kingdom (RIBOFEM) (2011). https://pubmed.ncbi.nlm.nih.gov/21525198/ DOI: 10.3945/ajcn.110.008409","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f7c9578-82bf-5e2d-b5c4-72a79fb4f6af","stable_key":"import-548ab9d6-3a9b-5bed-879c-17d03813b636","title":"Riboflavin: 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":"680cb6bc8249877f2410f551807f10d390fdd719014137d7414ba3420e29228d","revision_id":"7a61e299-908d-5372-860b-99ed190f9d7a","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}