{"id":"7b69ba41-6267-5fbd-ac7b-1e8d97b741b6","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-tt-homocysteine-response","predicate":"reduced_in_selected_tt_group","statement":"Riboflavin lowered plasma homocysteine in the MTHFR 677TT group by 22% overall; the lower-baseline-B2 subgroup showed a 40% decrease.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"1243432c-a1e6-5fe8-918d-6b4a481a51a6","mechanism_event_label":"In this trial, improving B2 supply lowered a folate-pathway blood marker in people with two copies of the studied MTHFR variant.","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":"1243432c-a1e6-5fe8-918d-6b4a481a51a6","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:b2-tt-homocysteine-response-event","event_type":"observed_intervention","label":"In this trial, improving B2 supply lowered a folate-pathway blood marker in people with two copies of the studied MTHFR variant.","description":"Riboflavin lowered plasma homocysteine in the MTHFR 677TT group by 22% overall; the lower-baseline-B2 subgroup showed a 40% decrease.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"9fc32b1a-0f08-544c-a361-1c728203b6ec","slug":"mthfr","display_name":"Methylenetetrahydrofolate reductase / MTHFR","entity_type_key":"protein"},"role":"variant_context","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"e2cd7179-f218-54e8-9ce9-7a836ae35fac","slug":"fad","display_name":"FAD","entity_type_key":"small_molecule"},"role":"cofactor","stoichiometry":null,"state_label":"","sequence_order":1,"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":2,"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":3,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"cross_nutrient","value_text":"B2 cofactor supply interacts with folate-cycle enzyme genotype.","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 677TT; common variant rather than complete loss of enzyme","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Small genotype strata; subgroup magnitude is not an expected response for every TT carrier. The trial did not test cardiovascular events.","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":"In this trial, improving B2 supply lowered a folate-pathway blood marker in people with two copies of the studied MTHFR variant.","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},{"dimension":"trigger_kind","value_text":"machinery_impairment","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"e798b058-c8ef-5799-82c4-2201740e0ab7","evidence_kind":"source_excerpt","locator":"Lines 1486-1498","start_line":1486,"end_line":1498,"excerpt":"### b2-tt-homocysteine-response\nRiboflavin lowered plasma homocysteine in the MTHFR 677TT group by 22% overall; the lower-baseline-B2 subgroup showed a 40% decrease.\nCondition category: machinery_impairment\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: In this trial, improving B2 supply lowered a folate-pathway blood marker in people with two copies of the studied MTHFR variant.\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: Small genotype strata; subgroup magnitude is not an expected response for every TT carrier. The trial did not test cardiovascular events.\nexposure: 1.6 mg/day riboflavin versus placebo for 12 weeks; experimental regimen.\ncross_nutrient: B2 cofactor supply interacts with folate-cycle enzyme genotype.\ngenotype: MTHFR 677TT; common variant rather than complete loss of enzyme\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}