{"id":"0a56f2fa-658f-518a-af36-71cdaec5ceec","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-cc-ct-homocysteine-nonresponse","predicate":"did_not_detectably_change_in_cc_ct","statement":"No homocysteine response was observed in the CC or CT groups despite improved riboflavin-status measures in all genotype groups.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"27596243-66eb-5db3-97e3-d932be618e2d","mechanism_event_label":"A better B2 test result did not automatically lower homocysteine in everyone.","subject":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"object":{"id":"5b635b42-bc0d-5c54-aa94-9cf76cd0ed47","slug":"homocysteine","display_name":"Homocysteine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"27596243-66eb-5db3-97e3-d932be618e2d","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-cc-ct-homocysteine-nonresponse-event","event_type":"observed_intervention","label":"A better B2 test result did not automatically lower homocysteine in everyone.","description":"No homocysteine response was observed in the CC or CT groups despite improved riboflavin-status measures in all genotype groups.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"9fc32b1a-0f08-544c-a361-1c728203b6ec","slug":"mthfr","display_name":"Methylenetetrahydrofolate reductase / MTHFR","entity_type_key":"protein"},"role":"genotype_context","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":"5b635b42-bc0d-5c54-aa94-9cf76cd0ed47","slug":"homocysteine","display_name":"Homocysteine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Folate-cycle biomarker response was genotype dependent.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Genotype-stratified randomized trial; 35 TT, 26 CT and 28 CC adults selected, ages 18-65.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"1.6 mg/day riboflavin versus placebo for 12 weeks; experimental regimen.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"genotype","value_text":"MTHFR 677CC or 677CT","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Null findings in modest samples do not prove an effect is impossible; context differs from the TT arm.","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":"A better B2 test result did not automatically lower homocysteine in everyone.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b2-mcnulty2006] Riboflavin lowers homocysteine in individuals homozygous for the MTHFR 677C->T polymorphism (2006). https://pubmed.ncbi.nlm.nih.gov/16380544/ DOI: 10.1161/circulationaha.105.580332","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Human clinical setting","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"4ee35e1d-280a-5737-b165-29f4c96453a2","evidence_kind":"source_excerpt","locator":"Lines 1500-1512","start_line":1500,"end_line":1512,"excerpt":"### b2-cc-ct-homocysteine-nonresponse\nNo homocysteine response was observed in the CC or CT groups despite improved riboflavin-status measures in all genotype groups.\nCondition category: normal\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: A better B2 test result did not automatically lower homocysteine in everyone.\norganism: Homo sapiens\ntissue_or_cell_type: Human clinical setting\nexperimental_model: Genotype-stratified randomized trial; 35 TT, 26 CT and 28 CC adults selected, ages 18-65.\nlimitations: Null findings in modest samples do not prove an effect is impossible; context differs from the TT arm.\nexposure: 1.6 mg/day riboflavin versus placebo for 12 weeks; experimental regimen.\ncross_nutrient: Folate-cycle biomarker response was genotype dependent.\ngenotype: MTHFR 677CC or 677CT\n[b2-mcnulty2006] Riboflavin lowers homocysteine in individuals homozygous for the MTHFR 677C->T polymorphism (2006). https://pubmed.ncbi.nlm.nih.gov/16380544/ DOI: 10.1161/circulationaha.105.580332","model_system":"Genotype-stratified randomized trial; 35 TT, 26 CT and 28 CC adults selected, ages 18-65.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b2-mcnulty2006] Riboflavin lowers homocysteine in individuals homozygous for the MTHFR 677C->T polymorphism (2006). https://pubmed.ncbi.nlm.nih.gov/16380544/ DOI: 10.1161/circulationaha.105.580332","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}