{"id":"a1b667b0-8ce8-5693-a071-d996fd5561f8","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:cal-carbonate-thyroxine-adsorption","predicate":"adsorbs","statement":"Thyroxine adsorbed to calcium carbonate under acidic in-vitro conditions.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"f10e2bdc-00ac-5794-b02c-1c79742dcca5","mechanism_event_label":"A calcium preparation can bind a thyroid medicine before absorption.","subject":{"id":"4ee1cbd0-1cec-58e1-9fee-bdb2c13db94d","slug":"calcium-carbonate","display_name":"Calcium carbonate","entity_type_key":"chemical_species"},"object":{"id":"f2b25f38-ec94-57d0-a46d-dd0fee45f01e","slug":"thyroxine","display_name":"T4","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"f10e2bdc-00ac-5794-b02c-1c79742dcca5","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:cal-carbonate-thyroxine-adsorption-event","event_type":"biochemical_relationship","label":"A calcium preparation can bind a thyroid medicine before absorption.","description":"Thyroxine adsorbed to calcium carbonate under acidic in-vitro conditions.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"4ee1cbd0-1cec-58e1-9fee-bdb2c13db94d","slug":"calcium-carbonate","display_name":"Calcium carbonate","entity_type_key":"chemical_species"},"role":"tested_input","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"f2b25f38-ec94-57d0-a46d-dd0fee45f01e","slug":"thyroxine","display_name":"T4","entity_type_key":"small_molecule"},"role":"measured_outcome","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"In-vitro adsorption arm accompanying a 20-patient study.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Supports an absorption-interference mechanism; does not show a systemic blockade of deiodinases.","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":"A calcium preparation can bind a thyroid medicine before absorption.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[cal-clin-singh2000] Effect of calcium carbonate on the absorption of levothyroxine (2000). https://pubmed.ncbi.nlm.nih.gov/10838651/ DOI: 10.1001/jama.283.21.2822","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free acidic solution","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"fc0d77cf-c57e-5d97-83e1-2aeec70f22ab","evidence_kind":"source_excerpt","locator":"Lines 1389-1398","start_line":1389,"end_line":1398,"excerpt":"### cal-carbonate-thyroxine-adsorption\nThyroxine adsorbed to calcium carbonate under acidic in-vitro conditions.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: A calcium preparation can bind a thyroid medicine before absorption.\norganism: Homo sapiens\ntissue_or_cell_type: Cell-free acidic solution\nexperimental_model: In-vitro adsorption arm accompanying a 20-patient study.\nlimitations: Supports an absorption-interference mechanism; does not show a systemic blockade of deiodinases.\n[cal-clin-singh2000] Effect of calcium carbonate on the absorption of levothyroxine (2000). https://pubmed.ncbi.nlm.nih.gov/10838651/ DOI: 10.1001/jama.283.21.2822","model_system":"In-vitro adsorption arm accompanying a 20-patient study.","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [cal-clin-singh2000] Effect of calcium carbonate on the absorption of levothyroxine (2000). https://pubmed.ncbi.nlm.nih.gov/10838651/ DOI: 10.1001/jama.283.21.2822","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}