{"id":"9a2dfa04-d6ea-5cc5-bc1f-512b83edf360","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-oral-im-metabolic-response","predicate":"both_routes_lowered_mma_and_homocysteine","statement":"At four months, mean MMA was 169 nmol/L with oral versus 265 with IM treatment; homocysteine was 10.6 versus 12.2 micromol/L. Oral-group MMA was significantly lower.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"b3e65830-ef49-5269-b48f-3c53e03f40c4","mechanism_event_label":"The biochemical response was recorded separately from the clinical response.","subject":{"id":"4cb4dfbc-6cd9-5bd5-98dc-d0a8fb6cfee4","slug":"cyanocobalamin","display_name":"Cyanocobalamin","entity_type_key":"small_molecule"},"object":{"id":"a2fda496-9308-54c5-b478-bc0b0c175570","slug":"methylmalonic-acid","display_name":"Methylmalonic acid","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"b3e65830-ef49-5269-b48f-3c53e03f40c4","stable_key":"7fc92b9e-9cbf-556e-8719-6b5244625250:b12-oral-im-metabolic-response-event","event_type":"observed_intervention","label":"The biochemical response was recorded separately from the clinical response.","description":"At four months, mean MMA was 169 nmol/L with oral versus 265 with IM treatment; homocysteine was 10.6 versus 12.2 micromol/L. Oral-group MMA was significantly lower.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"5b635b42-bc0d-5c54-aa94-9cf76cd0ed47","slug":"homocysteine","display_name":"Homocysteine","entity_type_key":"small_molecule"},"role":"measured_marker","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"4cb4dfbc-6cd9-5bd5-98dc-d0a8fb6cfee4","slug":"cyanocobalamin","display_name":"Cyanocobalamin","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"a2fda496-9308-54c5-b478-bc0b0c175570","slug":"methylmalonic-acid","display_name":"Methylmalonic acid","entity_type_key":"small_molecule"},"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":"experimental_model","value_text":"Randomized oral-versus-intramuscular study: 38 allocated; five subsequently identified as folate deficient excluded, leaving 18 oral and 15 injection participants.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Cyanocobalamin 2 mg orally each day for 120 days versus 1 mg IM on days 1, 3, 7, 10, 14, 21, 30, 60 and 90. Unequal cumulative exposures.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Different cumulative exposures prevent interpreting the result as inherent route superiority.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-b12","display_name":"Vitamin B12 (cobalamins)","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The biochemical response was recorded separately from the clinical response.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b12-kuzminski1998] Effective treatment of cobalamin deficiency with oral cobalamin (1998). https://pubmed.ncbi.nlm.nih.gov/9694707/ DOI: 10.1182/blood.v92.4.1191","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},{"dimension":"trigger_kind","value_text":"nutrient_deficiency","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"d8cf0991-9e93-59c9-a08a-4d710ed3ac39","evidence_kind":"source_excerpt","locator":"Lines 1697-1707","start_line":1697,"end_line":1707,"excerpt":"### b12-oral-im-metabolic-response\nAt four months, mean MMA was 169 nmol/L with oral versus 265 with IM treatment; homocysteine was 10.6 versus 12.2 micromol/L. Oral-group MMA was significantly lower.\nCondition category: nutrient_deficiency\nnutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The biochemical response was recorded separately from the clinical response.\norganism: Homo sapiens\ntissue_or_cell_type: Human blood or whole-person endpoints\nexperimental_model: Randomized oral-versus-intramuscular study: 38 allocated; five subsequently identified as folate deficient excluded, leaving 18 oral and 15 injection participants.\nlimitations: Different cumulative exposures prevent interpreting the result as inherent route superiority.\nexposure: Cyanocobalamin 2 mg orally each day for 120 days versus 1 mg IM on days 1, 3, 7, 10, 14, 21, 30, 60 and 90. Unequal cumulative exposures.\n[b12-kuzminski1998] Effective treatment of cobalamin deficiency with oral cobalamin (1998). https://pubmed.ncbi.nlm.nih.gov/9694707/ DOI: 10.1182/blood.v92.4.1191","model_system":"Randomized oral-versus-intramuscular study: 38 allocated; five subsequently identified as folate deficient excluded, leaving 18 oral and 15 injection participants.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b12-kuzminski1998] Effective treatment of cobalamin deficiency with oral cobalamin (1998). https://pubmed.ncbi.nlm.nih.gov/9694707/ DOI: 10.1182/blood.v92.4.1191","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"73145023-2982-5848-aff2-8d8875d6b9c5","stable_key":"import-7fc92b9e-9cbf-556e-8719-6b5244625250","title":"Vitamin B12: 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":"ad5b3a51d36e856aa7fdfd1cc23f690b094689bad87d28e1a621a54675a01c92","revision_id":"118bd616-0c13-549f-bfeb-bc439715b89c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}