{"id":"5f0f68fa-244d-5cb4-a864-618dcb557fec","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:low-calcium-diet-osteocyte-rankl-resorption","predicate":"deficiency_increases","statement":"A calcium-deficient diet increased osteoclasts and bone loss in adult mice; osteocyte-directed Rankl deletion blunted the response.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"57902cb3-d0a4-5b90-8d62-97bdb5d59788","mechanism_event_label":"When dietary calcium was severely restricted, osteocyte RANKL helped drive withdrawal from bone.","subject":{"id":"8e2a5a1f-cd49-5f28-8611-325266fb78a6","slug":"calcium","display_name":"Calcium","entity_type_key":"nutrient_element"},"object":{"id":"0adc6543-b0c1-5a49-9428-80f727ffeb9a","slug":"bone-resorption","display_name":"Osteoclastic bone resorption","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"57902cb3-d0a4-5b90-8d62-97bdb5d59788","stable_key":"434e1e27-eb90-583a-956b-62472726ffba:low-calcium-diet-osteocyte-rankl-resorption-event","event_type":"biochemical_relationship","label":"When dietary calcium was severely restricted, osteocyte RANKL helped drive withdrawal from bone.","description":"A calcium-deficient diet increased osteoclasts and bone loss in adult mice; 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Study references: [xiong2014] Osteocyte-derived RANKL is a critical mediator of the increased bone resorption caused by dietary calcium deficiency (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC4125539/ DOI: 10.1016/j.bone.2014.06.006","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":[{"id":"ecc4811d-2e6c-5c7a-b20f-42ee96155db1","title":"PTH-associated resorption versus intermittent PTH support of osteoblast survival","kind":"context_difference","status":"open","why":"Calcium restriction with secondary hyperparathyroidism and daily PTH injections examine different exposure patterns and cellular outcomes.","resolution":"Curation interpretation: retain the bone-resorption and osteoblast-survival findings with their separate experimental contexts; neither supports a universal direction of PTH effects on bone mass.","created_at":"2026-09-17 08:08:54","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/ecc4811d-2e6c-5c7a-b20f-42ee96155db1","sides":[{"conflict_id":"ecc4811d-2e6c-5c7a-b20f-42ee96155db1","ordinal":0,"label":"When dietary calcium was severely restricted, osteocyte RANKL helped drive withdrawal from bone.","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","start_line":1070,"end_line":1079,"quote":"### low-calcium-diet-osteocyte-rankl-resorption\nA calcium-deficient diet increased osteoclasts and bone loss in adult mice; osteocyte-directed Rankl deletion blunted the response.\nCondition category: nutrient_deficiency\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: When dietary calcium was severely restricted, osteocyte RANKL helped drive withdrawal from bone.\norganism: Mus musculus\ntissue_or_cell_type: Adult cortical and cancellous bone\nexperimental_model: 30 days of 0.01% versus 0.516% dietary calcium\nlimitations: Mouse diet and Cre-targeting scope limit human generalization; bone loss was blunted, not necessarily abolished.\n[xiong2014] Osteocyte-derived RANKL is a critical mediator of the increased bone resorption caused by dietary calcium deficiency (2014). https://pmc.ncbi.nlm.nih.gov/articles/PMC4125539/ DOI: 10.1016/j.bone.2014.06.006","source_key":"import-434e1e27-eb90-583a-956b-62472726ffba","source_title":"Calcium: mechanism-first literature curation (2026-09-17)","claim_ids":["5f0f68fa-244d-5cb4-a864-618dcb557fec"]},{"conflict_id":"ecc4811d-2e6c-5c7a-b20f-42ee96155db1","ordinal":1,"label":"Intermittent PTH exposure can prolong the survival of bone-forming cells.","revision_id":"543ec48b-4f70-5197-9d76-f5a3c443664c","start_line":1093,"end_line":1102,"quote":"### intermittent-pth-reduces-osteoblast-apoptosis\nDaily PTH(1-34) injections reduced osteoblast apoptosis and increased bone formation in the studied adult mouse strains.\nCondition category: normal\nnutrient_topic: Calcium research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Intermittent PTH exposure can prolong the survival of bone-forming cells.\norganism: Mus musculus; rodent and human cell corroboration\ntissue_or_cell_type: Cancellous bone osteoblasts\nexperimental_model: Daily PTH(1-34) administration and cell assays\nlimitations: An experimental dosing context; it must not be generalized to sustained endogenous PTH elevation or calcium supplementation.\n[jilka1999] Increased bone formation by prevention of osteoblast apoptosis with parathyroid hormone (1999). https://www.jci.org/articles/view/6610 DOI: 10.1172/JCI6610","source_key":"import-434e1e27-eb90-583a-956b-62472726ffba","source_title":"Calcium: mechanism-first literature curation (2026-09-17)","claim_ids":["4e932f73-b073-5d84-9509-6b5687cdb6e5"]}]}],"corrections":[],"research":null}