{"claimId":"clm_ec_b8-vitd-cold","version":1,"status":"current","verdict":"Vitamin D for cold prevention: Grade — at moderate certainty. Meta-analysis of 12 RCTs (41,552 participants) in older adults: vitamin D supplementation probably does NOT reduce the incidence of acute respiratory infections overall (RR 0.99, moderate certainty), with no significant subgroup effect by baseline vitamin D level, dose, or duration. A non-significant signal for benefit specifically in vitamin-D-deficient individuals was noted but not confirmed.","direction":"null","magnitude":{"metric":"other","value":null,"unit":"","ci95":null,"humanReadable":"Meta-analysis of 12 RCTs (41,552 participants) in older adults: vitamin D supplementation probably does NOT reduce the incidence of acute respiratory infections overall (RR 0.99, moderate certainty), with no significant subgroup effect by baseline vitamin D level, dose, or duration. A non-significant signal for benefit specifically in vitamin-D-deficient individuals was noted but not confirmed.","baselineAbsoluteRisk":null},"certainty":"moderate","clinicalMeaning":"no_established_threshold","applicability":{"appliesTo":["older adults"],"doesNotApply":["children"],"unknown":["pregnancy"]},"safetyQualifiers":[],"evidenceBundleId":"eb_ec_b8-vitd-cold","citations":[{"pmid":"38787821","design":"peer-reviewed"}],"reviewedBy":{"name":"Substrate editorial","credential":"Independent research collective"},"reviewedAt":"2026-07-16T16:40:42.048Z","dateModified":"2026-07-16T16:40:42.048Z","methodologyVersion":"v1","methodologyDoi":"https://doi.org/10.5281/zenodo.21364236","canonicalUrl":"https://evidencebased.info/interventions/vitamin-d/cold-prevention","attribution":"Substrate (evidencebased.info), claim clm_ec_b8-vitd-cold v1, reviewed 2026-07-16","license":"CC-BY-4.0 proposed; reuse license pending governance ratification","dataSource":"live"}