{"id":"cdc245d8-5393-5a2b-bd4b-10c9094079f1","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:cal-food-spinach-absorption","predicate":"has_reported_effect_on","statement":"Calcium absorption from the tested spinach meal was lower than from milk at equal calcium load.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"d598bc9b-d0fc-5d03-b3e0-a6fd28743577","mechanism_event_label":"Equal calcium on a food label need not mean equal absorption.","subject":{"id":"8e2a5a1f-cd49-5f28-8611-325266fb78a6","slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"},"object":{"id":"53d44ad2-3648-5c31-8328-bcc1344961df","slug":"intestinal-calcium-absorption","display_name":"Intestinal calcium absorption","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"d598bc9b-d0fc-5d03-b3e0-a6fd28743577","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:cal-food-spinach-absorption-event","event_type":"observed_intervention","label":"Equal calcium on a food label need not mean equal absorption.","description":"Calcium absorption from the tested spinach meal was lower than from milk at equal calcium load.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"8e2a5a1f-cd49-5f28-8611-325266fb78a6","slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"},"role":"tested_input","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"53d44ad2-3648-5c31-8328-bcc1344961df","slug":"intestinal-calcium-absorption","display_name":"Intestinal calcium absorption","entity_type_key":"cellular_process"},"role":"measured_outcome","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"e359bc15-e675-5d83-b0fe-1d70814e130b","slug":"calcium-ion","display_name":"Calcium ion","entity_type_key":"ion"},"role":"absorbed_species","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"9c8d2b72-517d-5bb6-8589-cabd98267f65","slug":"oxalate","display_name":"Oxalate","entity_type_key":"ion"},"role":"food_matrix_component","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"13-adult crossover; 200 mg calcium per test meal, double-isotope measurement.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Mean fractional absorption: spinach 5.1%, milk 27.6%; oxalate slightly exceeded calcium stoichiometrically in tested spinach.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Food-matrix comparison; oxalate binding was inferred from composition, not isolated experimentally. Not a comparison of every plant food.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Calcium research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Equal calcium on a food label need not mean equal absorption.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[cal-clin-heaney1988] Calcium absorbability from spinach (1988). https://pubmed.ncbi.nlm.nih.gov/3354496/ DOI: 10.1093/ajcn/47.4.707","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Human clinical or absorption endpoint","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"20b2013b-85e1-5bd2-8225-609eed38cfa4","evidence_kind":"source_excerpt","locator":"Lines 1152-1162","start_line":1152,"end_line":1162,"excerpt":"### cal-food-spinach-absorption\nCalcium absorption from the tested spinach meal was lower than from milk at equal calcium load.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Equal calcium on a food label need not mean equal absorption.\norganism: Homo sapiens\ntissue_or_cell_type: Human clinical or absorption endpoint\nexperimental_model: 13-adult crossover; 200 mg calcium per test meal, double-isotope measurement.\nlimitations: Food-matrix comparison; oxalate binding was inferred from composition, not isolated experimentally. Not a comparison of every plant food.\nexposure: Mean fractional absorption: spinach 5.1%, milk 27.6%; oxalate slightly exceeded calcium stoichiometrically in tested spinach.\n[cal-clin-heaney1988] Calcium absorbability from spinach (1988). https://pubmed.ncbi.nlm.nih.gov/3354496/ DOI: 10.1093/ajcn/47.4.707","model_system":"13-adult crossover; 200 mg calcium per test meal, double-isotope measurement.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [cal-clin-heaney1988] Calcium absorbability from spinach (1988). https://pubmed.ncbi.nlm.nih.gov/3354496/ DOI: 10.1093/ajcn/47.4.707","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"3c083fa0-59c6-50e9-af42-678d0e3c1006","stable_key":"import-434e1e27-eb90-583a-956b-62472726ffba","title":"Calcium: mechanism-first literature curation (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":"965c934d6b147f2b62f8d45ce6d7a87681a600bfe5c46a585b4704889afd3fc1","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}