{"id":"9162cad2-732c-5c1b-92b2-0d24982db98c","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-mk4-serum","predicate":"did_not_measurably_increase","statement":"MK-4 was not detected in serum after the tested 420-microgram dose and serum MK-4 did not increase with the seven-day 60-microgram regimen.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"ea62cec8-9b10-5f1a-8878-4340c837cf2f","mechanism_event_label":"The blood test behaved differently for MK-4; that does not tell us that none reached tissues.","subject":{"id":"5155b9d1-e835-54b4-9f61-4cf35b3e5227","slug":"menaquinone-4","display_name":"Menaquinone-4 / MK-4 / menatetrenone","entity_type_key":"small_molecule"},"object":{"id":"cb001bb8-cd8c-52cc-a8e1-7ccc217bed3f","slug":"mk4-serum-concentration","display_name":"Serum menaquinone-4 concentration","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"ea62cec8-9b10-5f1a-8878-4340c837cf2f","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-mk4-serum-event","event_type":"observed_intervention","label":"The blood test behaved differently for MK-4; that does not tell us that none reached tissues.","description":"MK-4 was not detected in serum after the tested 420-microgram dose and serum MK-4 did not increase with the seven-day 60-microgram regimen.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"5155b9d1-e835-54b4-9f61-4cf35b3e5227","slug":"menaquinone-4","display_name":"Menaquinone-4 / MK-4 / menatetrenone","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"cb001bb8-cd8c-52cc-a8e1-7ccc217bed3f","slug":"mk4-serum-concentration","display_name":"Serum menaquinone-4 concentration","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/k2-research/23140417.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e72bb9c0cc5800cba0605d7abba2c4e6c113dda5fa0e9b4a3afff898b23a97c4\", \"start_char\": 0, \"end_char\": 1328, \"text_sha256\": \"e72bb9c0cc5800cba0605d7abba2c4e6c113dda5fa0e9b4a3afff898b23a97c4\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Single-dose and seven-day nutritional-dose comparison","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"420 micrograms single dose or 60 micrograms/day for seven days; MK-4 versus MK-7","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Small parallel groups; equal mass is not equal molar dose. Undetectable serum MK-4 does not prove absent absorption, absent tissue delivery or clinical ineffectiveness.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Healthy young Japanese women","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The blood test behaved differently for MK-4; that does not tell us that none reached tissues.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[k2-p23140417] Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. (2012). https://pubmed.ncbi.nlm.nih.gov/23140417/ DOI: 10.1186/1475-2891-11-93","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Serum vitamin K concentrations","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"0a037eac-40bd-5b28-a02a-80294f03a55b","evidence_kind":"source_excerpt","locator":"Lines 279-290","start_line":279,"end_line":290,"excerpt":"### k2-mk4-serum\nMK-4 was not detected in serum after the tested 420-microgram dose and serum MK-4 did not increase with the seven-day 60-microgram regimen.\nCondition category: normal\nnutrient_topic: Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The blood test behaved differently for MK-4; that does not tell us that none reached tissues.\norganism: Healthy young Japanese women\ntissue_or_cell_type: Serum vitamin K concentrations\nexperimental_model: Single-dose and seven-day nutritional-dose comparison\nlimitations: Small parallel groups; equal mass is not equal molar dose. Undetectable serum MK-4 does not prove absent absorption, absent tissue delivery or clinical ineffectiveness.\nexposure: 420 micrograms single dose or 60 micrograms/day for seven days; MK-4 versus MK-7\nevidence_span: {\"source_cache\": \"artifacts/k2-research/23140417.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"e72bb9c0cc5800cba0605d7abba2c4e6c113dda5fa0e9b4a3afff898b23a97c4\", \"start_char\": 0, \"end_char\": 1328, \"text_sha256\": \"e72bb9c0cc5800cba0605d7abba2c4e6c113dda5fa0e9b4a3afff898b23a97c4\"}\n[k2-p23140417] Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. (2012). https://pubmed.ncbi.nlm.nih.gov/23140417/ DOI: 10.1186/1475-2891-11-93","model_system":"Single-dose and seven-day nutritional-dose comparison","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [k2-p23140417] Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. (2012). https://pubmed.ncbi.nlm.nih.gov/23140417/ DOI: 10.1186/1475-2891-11-93","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dfeae572-af3d-5042-a10e-e67596f9ab28","stable_key":"import-4fef8d72-f107-5eb5-b2fb-483ca85465e0","title":"Vitamin K2: menaquinone forms, carboxylation, recycling 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":"dc31aff21110d09b025c177e03b4c5ca8349d52bf5f962285fdbfcf660c0e4f6","revision_id":"850887db-34f6-55aa-9d3e-b8fd3a4a5de3","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}