{"id":"e22dffe3-5f5e-59d1-b96f-ad28c35b12c0","stable_key":"e13b03e1-a614-543a-ac1b-97df18cfe30d:iron-nonanemic-fatigue","predicate":"reduced","statement":"Fatigue scores decreased 47.7% with iron versus 28.8% with placebo; the between-group difference was significant (P=0.02).","claim_class":"observational","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"2d4e3229-5dda-5ef2-b6da-b98b21aa248b","mechanism_event_label":"Normal-range hemoglobin did not exclude an iron-responsive fatigue outcome in this selected group.","subject":{"id":"f20cb550-cb6b-5eab-a4d7-27537a5eb14b","slug":"ferrous-sulfate","display_name":"Ferrous sulfate","entity_type_key":"chemical_species"},"object":{"id":"bd70fb46-0723-5afa-a138-a2046f9e1794","slug":"fatigue-severity","display_name":"Self-reported fatigue severity","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"2d4e3229-5dda-5ef2-b6da-b98b21aa248b","stable_key":"e13b03e1-a614-543a-ac1b-97df18cfe30d:iron-nonanemic-fatigue-event","event_type":"observed_intervention","label":"Normal-range hemoglobin did not exclude an iron-responsive fatigue outcome in this selected group.","description":"Fatigue scores decreased 47.7% with iron versus 28.8% with placebo; the between-group difference was significant (P=0.02).","status":"provisional","compartment":null,"participants":[{"entity":{"id":"f20cb550-cb6b-5eab-a4d7-27537a5eb14b","slug":"ferrous-sulfate","display_name":"Ferrous sulfate","entity_type_key":"chemical_species"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"bd70fb46-0723-5afa-a138-a2046f9e1794","slug":"fatigue-severity","display_name":"Self-reported fatigue severity","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"biomarker_context","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/iron-research/22777991.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"7d8d360cee2d71d5cf1d7b19bbd5c740164d24c16daf98fe4519551573f8fb75\", \"start_char\": 0, \"end_char\": 1708, \"text_sha256\": \"7d8d360cee2d71d5cf1d7b19bbd5c740164d24c16daf98fe4519551573f8fb75\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Randomized placebo-controlled 12-week trial","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Ferritin below 50 micrograms/L, hemoglobin above 12 g/dL; 80 mg elemental iron/day versus placebo","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Trial inclusion criteria are not a universal deficiency threshold. No significant improvement in depression, anxiety or overall quality of life.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Iron research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"iron","display_name":"Iron","entity_type_key":"nutrient_element"}},{"dimension":"organism","value_text":"198 nonanemic menstruating women with fatigue","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Normal-range hemoglobin did not exclude an iron-responsive fatigue outcome in this selected group.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[iron-p22777991] Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. (2012). https://pubmed.ncbi.nlm.nih.gov/22777991/ DOI: 10.1503/cmaj.110950","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Reported symptoms and blood markers","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"biomarker_context","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null}],"evidence":[{"id":"9f596a13-c241-5998-8e05-6ab38c619ca9","evidence_kind":"source_excerpt","locator":"Lines 1317-1328","start_line":1317,"end_line":1328,"excerpt":"### iron-nonanemic-fatigue\nFatigue scores decreased 47.7% with iron versus 28.8% with placebo; the between-group difference was significant (P=0.02).\nCondition category: biomarker_context\nnutrient_topic: Iron research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Normal-range hemoglobin did not exclude an iron-responsive fatigue outcome in this selected group.\norganism: 198 nonanemic menstruating women with fatigue\ntissue_or_cell_type: Reported symptoms and blood markers\nexperimental_model: Randomized placebo-controlled 12-week trial\nlimitations: Trial inclusion criteria are not a universal deficiency threshold. No significant improvement in depression, anxiety or overall quality of life.\nexposure: Ferritin below 50 micrograms/L, hemoglobin above 12 g/dL; 80 mg elemental iron/day versus placebo\nevidence_span: {\"source_cache\": \"artifacts/iron-research/22777991.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"7d8d360cee2d71d5cf1d7b19bbd5c740164d24c16daf98fe4519551573f8fb75\", \"start_char\": 0, \"end_char\": 1708, \"text_sha256\": \"7d8d360cee2d71d5cf1d7b19bbd5c740164d24c16daf98fe4519551573f8fb75\"}\n[iron-p22777991] Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. (2012). https://pubmed.ncbi.nlm.nih.gov/22777991/ DOI: 10.1503/cmaj.110950","model_system":"Randomized placebo-controlled 12-week trial","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [iron-p22777991] Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial. (2012). https://pubmed.ncbi.nlm.nih.gov/22777991/ DOI: 10.1503/cmaj.110950","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"1560864c-91d1-58dc-90c4-49bf61aba3de","stable_key":"import-e13b03e1-a614-543a-ac1b-97df18cfe30d","title":"Iron: absorption, trafficking, iron-dependent enzymes 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. 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