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(2010). https://pubmed.ncbi.nlm.nih.gov/20488910/ DOI: 10.1136/bmj.c2181","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Whole body","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":"a398bd15-d608-57c3-8164-03dd1e7b8c70","evidence_kind":"source_excerpt","locator":"Lines 1061-1072","start_line":1061,"end_line":1072,"excerpt":"### metformin-b12-folate-decrease\nMetformin was associated with a mean decrease in folate concentration of 5%, although after adjustment for body mass index and smoking no significant effect on folate remained.\nCondition category: nutrient_deficiency\nnutrient_topic: Metformin research collection; topical membership is not evidence of a direct clinical effect, and pharmacological exposure is not dietary intake.\nplain_language: A small folate fall was seen but did not survive adjustment.\norganism: Human\ntissue_or_cell_type: Whole body\nexperimental_model: Multicentre randomised placebo-controlled trial, 390 people with type 2 diabetes on insulin\nlimitations: The strongest available human causal evidence for the B12 effect. It measured concentrations and deficiency incidence, not clinical deficiency syndromes.\nexposure: 850 mg metformin three times daily for 4.3 years versus placebo\nevidence_span: {\"source_cache\": \"artifacts/metformin-research/20488910.abstract.txt\", \"locator\": \"Indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"6c9e09d44fe1103e6927321e925e69e31c38d1a688fd2ac18ea96927098de922\", \"start_char\": 0, \"end_char\": 2518, \"text_sha256\": \"6c9e09d44fe1103e6927321e925e69e31c38d1a688fd2ac18ea96927098de922\"}\n[metformin-p20488910] Long term treatment with metformin in patients with type 2 diabetes and risk of vitamin B-12 deficiency: randomised placebo controlled trial. 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