{"id":"fb0f74db-bccb-54ac-aeb8-1c6e6f16745c","stable_key":"7edf94bb-95c8-5234-9161-9eb338bb9b36:boron-human-calcium-sparing-1987","predicate":"reduces","statement":"A 3 mg/day boron supplement after prolonged low intake reduced urinary calcium in the 1987 postmenopausal feeding study, apparently more strongly with low magnesium intake.","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"negative","is_public":true,"mechanism_event_id":"2773eda7-9f54-5546-b063-ae73b0954a44","mechanism_event_label":"The women lost less calcium in urine under this particular feeding regimen.","subject":{"id":"5144a867-de17-599d-baec-68500e3d40bd","slug":"boron","display_name":"Boron","entity_type_key":"nutrient_element"},"object":{"id":"538fbe5c-11da-5aa5-990f-e8be1aa7bc5a","slug":"urinary-calcium-excretion","display_name":"Urinary calcium excretion","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"2773eda7-9f54-5546-b063-ae73b0954a44","stable_key":"7edf94bb-95c8-5234-9161-9eb338bb9b36:boron-human-calcium-sparing-1987-event","event_type":"observed_intervention","label":"The women lost less calcium in urine under this particular feeding regimen.","description":"A 3 mg/day boron supplement after prolonged low intake reduced urinary calcium in the 1987 postmenopausal feeding study, apparently more strongly with low magnesium intake.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"1f0c42f0-eaf3-5b86-966d-7ffc8a84872b","slug":"magnesium","display_name":"Magnesium","entity_type_key":"nutrient_element"},"role":"dietary_context","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"5144a867-de17-599d-baec-68500e3d40bd","slug":"boron","display_name":"Boron","entity_type_key":"nutrient_element"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"538fbe5c-11da-5aa5-990f-e8be1aa7bc5a","slug":"urinary-calcium-excretion","display_name":"Urinary calcium excretion","entity_type_key":"cellular_process"},"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":"evidence_span","value_text":"{\"source_cache\": \"artifacts/boron-research/3678698.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"8f95ac01b63502b366e2bd79785b7203deb793d258df065f13cc1e0123c89fb7\", \"start_char\": 0, \"end_char\": 1373, \"text_sha256\": \"8f95ac01b63502b366e2bd79785b7203deb793d258df065f13cc1e0123c89fb7\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Sequential controlled feeding in a metabolic unit; 12 postmenopausal women","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"About 0.25 mg boron/day for 119 days, then 3 mg/day supplement; seven low-magnesium and five adequate-magnesium participants","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Small sequential study, not a fracture or bone-density trial. Diet and magnesium status matter. Later studies did not consistently reproduce the reported effects.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Boron research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"boron","display_name":"Boron","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"Human","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The women lost less calcium in urine under this particular feeding regimen.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[boron-p3678698] Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women. (1987). https://pubmed.ncbi.nlm.nih.gov/3678698/ DOI: 10.1096/fasebj.1.5.3678698","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Systemic mineral balance and circulating hormones","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":"9daad7c7-4984-586d-ba63-b53d0a6ee8a0","evidence_kind":"source_excerpt","locator":"Lines 599-610","start_line":599,"end_line":610,"excerpt":"### boron-human-calcium-sparing-1987\nA 3 mg/day boron supplement after prolonged low intake reduced urinary calcium in the 1987 postmenopausal feeding study, apparently more strongly with low magnesium intake.\nCondition category: nutrient_deficiency\nnutrient_topic: Boron research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The women lost less calcium in urine under this particular feeding regimen.\norganism: Human\ntissue_or_cell_type: Systemic mineral balance and circulating hormones\nexperimental_model: Sequential controlled feeding in a metabolic unit; 12 postmenopausal women\nlimitations: Small sequential study, not a fracture or bone-density trial. Diet and magnesium status matter. Later studies did not consistently reproduce the reported effects.\nexposure: About 0.25 mg boron/day for 119 days, then 3 mg/day supplement; seven low-magnesium and five adequate-magnesium participants\nevidence_span: {\"source_cache\": \"artifacts/boron-research/3678698.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"8f95ac01b63502b366e2bd79785b7203deb793d258df065f13cc1e0123c89fb7\", \"start_char\": 0, \"end_char\": 1373, \"text_sha256\": \"8f95ac01b63502b366e2bd79785b7203deb793d258df065f13cc1e0123c89fb7\"}\n[boron-p3678698] Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women. (1987). https://pubmed.ncbi.nlm.nih.gov/3678698/ DOI: 10.1096/fasebj.1.5.3678698","model_system":"Sequential controlled feeding in a metabolic unit; 12 postmenopausal women","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [boron-p3678698] Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women. (1987). https://pubmed.ncbi.nlm.nih.gov/3678698/ DOI: 10.1096/fasebj.1.5.3678698","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"2d96c547-aeec-5d8b-9d31-1288da209f89","stable_key":"import-7edf94bb-95c8-5234-9161-9eb338bb9b36","title":"Boron: chemistry, nutrient interactions, low-intake studies and mechanistic uncertainties (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":"0a32c1c5c70cfb4a378f6ace35cf5b75d90ed3065ada91b9f9f64015d603c8e3","revision_id":"38f316f2-4344-542e-a638-0ac5402f678d","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[{"id":"72d4b636-d451-533d-bd95-24240ac3fb26","title":"Does boron supplementation consistently reduce urinary calcium after low intake?","kind":"contradiction","status":"open","why":"The 1987 study reported lower urinary calcium after boron supplementation. A 1993 follow-up designed to examine the proposed effect found no mineral response. Differences in low-intake duration, background diet, magnesium status and calcium balance may matter, but no single explanation has been established. The later magnesium-dependent reversal further limits any universal calcium-sparing claim.","resolution":"Keep the positive and null findings linked to their study locations. Report an inconsistent, diet-dependent human response; neither declare the first paper an author error nor infer that boron universally prevents bone loss. Comments and proposed mechanisms should distinguish tested explanations from speculation.","created_at":"2026-09-17 19:08:59","record_type":"conflict","display_label":"Recorded conflict","record_url":"/conflicts/72d4b636-d451-533d-bd95-24240ac3fb26","sides":[{"conflict_id":"72d4b636-d451-533d-bd95-24240ac3fb26","ordinal":0,"label":"The women lost less calcium in urine under this particular feeding regimen.","revision_id":"38f316f2-4344-542e-a638-0ac5402f678d","start_line":599,"end_line":610,"quote":"### boron-human-calcium-sparing-1987\nA 3 mg/day boron supplement after prolonged low intake reduced urinary calcium in the 1987 postmenopausal feeding study, apparently more strongly with low magnesium intake.\nCondition category: nutrient_deficiency\nnutrient_topic: Boron research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The women lost less calcium in urine under this particular feeding regimen.\norganism: Human\ntissue_or_cell_type: Systemic mineral balance and circulating hormones\nexperimental_model: Sequential controlled feeding in a metabolic unit; 12 postmenopausal women\nlimitations: Small sequential study, not a fracture or bone-density trial. Diet and magnesium status matter. Later studies did not consistently reproduce the reported effects.\nexposure: About 0.25 mg boron/day for 119 days, then 3 mg/day supplement; seven low-magnesium and five adequate-magnesium participants\nevidence_span: {\"source_cache\": \"artifacts/boron-research/3678698.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"8f95ac01b63502b366e2bd79785b7203deb793d258df065f13cc1e0123c89fb7\", \"start_char\": 0, \"end_char\": 1373, \"text_sha256\": \"8f95ac01b63502b366e2bd79785b7203deb793d258df065f13cc1e0123c89fb7\"}\n[boron-p3678698] Effect of dietary boron on mineral, estrogen, and testosterone metabolism in postmenopausal women. (1987). https://pubmed.ncbi.nlm.nih.gov/3678698/ DOI: 10.1096/fasebj.1.5.3678698","source_key":"import-7edf94bb-95c8-5234-9161-9eb338bb9b36","source_title":"Boron: chemistry, nutrient interactions, low-intake studies and mechanistic uncertainties (2026-09-17)","claim_ids":["fb0f74db-bccb-54ac-aeb8-1c6e6f16745c"]},{"conflict_id":"72d4b636-d451-533d-bd95-24240ac3fb26","ordinal":1,"label":"This follow-up did not reproduce the earlier calcium-sparing finding.","revision_id":"38f316f2-4344-542e-a638-0ac5402f678d","start_line":703,"end_line":714,"quote":"### boron-human-calcium-null-1993\nIncreasing boron intake from 0.33 to 3.33 mg/day did not alter the measured mineral absorption or excretion endpoints in the 1993 follow-up study.\nCondition category: nutrient_deficiency\nnutrient_topic: Boron research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: This follow-up did not reproduce the earlier calcium-sparing finding.\norganism: Human postmenopausal volunteers\ntissue_or_cell_type: Mineral balance, hormones and bone-turnover markers\nexperimental_model: Metabolic-unit low-intake/supplementation follow-up\nlimitations: Small, short sequential study. The background diet produced positive calcium balance with increased urinary calcium; the authors proposed that this could mask a boron effect, but did not prove the explanation.\nexposure: 0.33 mg boron/day for three weeks, then an additional 3 mg/day for three weeks\nevidence_span: {\"source_cache\": \"artifacts/boron-research/8329361.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"3e6e2137f75699ea6dce582375f335a85139fea1cfa7ec502f033e8bfe026d63\", \"start_char\": 0, \"end_char\": 1079, \"text_sha256\": \"3e6e2137f75699ea6dce582375f335a85139fea1cfa7ec502f033e8bfe026d63\"}\n[boron-p8329361] The influence of a low-boron diet and boron supplementation on bone, major mineral and sex steroid metabolism in postmenopausal women. (1993). https://pubmed.ncbi.nlm.nih.gov/8329361/ DOI: 10.1079/bjn19930087","source_key":"import-7edf94bb-95c8-5234-9161-9eb338bb9b36","source_title":"Boron: chemistry, nutrient interactions, low-intake studies and mechanistic uncertainties (2026-09-17)","claim_ids":["48e44344-e475-5467-9dda-d851989c7df1"]},{"conflict_id":"72d4b636-d451-533d-bd95-24240ac3fb26","ordinal":2,"label":"The calcium response changed direction with the magnesium diet.","revision_id":"38f316f2-4344-542e-a638-0ac5402f678d","start_line":664,"end_line":675,"quote":"### boron-calcium-magnesium-context-1997\nBoron supplementation lowered the fraction of dietary calcium excreted in urine under basal magnesium intake but increased that fraction with magnesium supplementation.\nCondition category: nutrient_deficiency\nnutrient_topic: Boron research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The calcium response changed direction with the magnesium diet.\norganism: Human\ntissue_or_cell_type: Mineral balance, blood and excreta\nexperimental_model: Metabolic-ward feeding; 11 postmenopausal volunteers\nlimitations: Small study with multiple dietary periods and supplements. Do not assume independence from related reports from the same research program. Urine composition is not a kidney-stone clinical endpoint.\nexposure: 167-day study; basal 0.36 mg B and 109 mg Mg/8400 kJ; 3 mg/day B supplement in last two 24-day periods; magnesium supplement 0 or 200 mg/day\nevidence_span: {\"source_cache\": \"artifacts/boron-research/9062533.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"a23cd1fe09277bdd83b690746d4bbaf4742cdd74e51d5b27ee898bd87208b2be\", \"start_char\": 0, \"end_char\": 1720, \"text_sha256\": \"a23cd1fe09277bdd83b690746d4bbaf4742cdd74e51d5b27ee898bd87208b2be\"}\n[boron-p9062533] Metabolic responses of postmenopausal women to supplemental dietary boron and aluminum during usual and low magnesium intake: boron, calcium, and magnesium absorption and retention and blood mineral concentrations. (1997). https://pubmed.ncbi.nlm.nih.gov/9062533/ DOI: 10.1093/ajcn/65.3.803","source_key":"import-7edf94bb-95c8-5234-9161-9eb338bb9b36","source_title":"Boron: chemistry, nutrient interactions, low-intake studies and mechanistic uncertainties (2026-09-17)","claim_ids":["e0900f16-c3bb-5b5a-a901-d25c31ec619a"]}]}],"corrections":[],"research":null}