{"entity":{"id":"vitamin-d-omega3-supplementation","kind":"technology","name":"Vitamin D and omega-3 supplementation","aka":[],"tldr":"The largest trial of vitamin D and fish-oil pills found they did not prevent cancer. A possible reduction in cancer deaths, and hints of benefit after a digestive cancer diagnosis, keep the question alive.","summary":"VITAL (NEJM 2019) randomised 25,871 US adults to vitamin D3 2000 IU/day and/or omega-3 fatty acids 1 g/day for a median 5.3 years: invasive cancer incidence was unchanged (HR 0.96 for vitamin D, 1.03 for omega-3). Total cancer mortality was numerically lower with vitamin D, reaching significance only in analyses excluding the first two years (HR 0.75), an exploratory finding, and a pooled meta-analysis of vitamin D trials suggests a 10-15% reduction in cancer death but not incidence. In patients already diagnosed, the Japanese AMATERASU (digestive tract cancers) and SUNSHINE (metastatic colorectal, high-dose vitamin D with chemotherapy) trials were null on their primary endpoints with subgroup hints; the phase 3 SOLARIS trial of high-dose vitamin D with FOLFOX-bevacizumab in metastatic colorectal cancer was negative (2025). Omega-3 supplements have no consistent cancer prevention effect; in cachexia they preserve weight in some trials but not function. The defensible summary: correct deficiency, do not expect prevention from supplements.","status":"phase-3","asOf":"2026-09-08","wikipedia":"https://en.wikipedia.org/wiki/Vitamin_D","links":[{"label":"VITAL (NEJM 2019)","url":"https://doi.org/10.1056/NEJMoa1809944"},{"label":"SUNSHINE (JAMA 2019)","url":"https://doi.org/10.1001/jama.2019.2402"}],"tags":[],"related":["idea-reg-vitamin-d-digestive-cancer-biomarker-trial"],"cancers":["colorectal","gastric","esophageal","breast-hr-positive","prostate"],"sections":["nutrition-lifestyle","prevention"],"technologies":["chemoprevention"],"targets":[],"drugs":["folfox","bevacizumab"],"companies":[],"institutions":[],"pathways":[],"terms":["unproven-diet-claims"],"trials":["vital"],"people":[],"bottlenecks":["b-negative-results","b-misinformation"],"keyPapers":["paper-manson-n-engl-j-med","paper-ng-jama"],"journals":[],"dependsOn":[],"notes":[],"principle":"Vitamin D acts through the vitamin D receptor on cell differentiation, proliferation and immune modulation; omega-3 fatty acids reduce pro-inflammatory eicosanoids. Neither has translated into reduced cancer incidence in randomised trials.","strengths":["Definitive randomised evidence on incidence","Cheap and safe at tested doses","Mortality signal worth a purpose-designed trial"],"limitations":["Primary prevention endpoints null","Secondary and subgroup findings drive continued hype","Baseline deficiency rarely stratified"]},"route":"/technologies/vitamin-d-omega3-supplementation/","neighbours":{"idea":[{"id":"idea-reg-vitamin-d-digestive-cancer-biomarker-trial","kind":"idea","name":"A biomarker-directed trial of vitamin D after surgery for digestive tract cancers","route":"/ideas/idea-reg-vitamin-d-digestive-cancer-biomarker-trial/"}],"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"esophageal","kind":"cancer","name":"Oesophageal cancer","route":"/cancers/esophageal/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"}],"section":[{"id":"nutrition-lifestyle","kind":"section","name":"Diet, Exercise & Lifestyle","route":"/fronts/nutrition-lifestyle/"},{"id":"prevention","kind":"section","name":"Prevention & Risk","route":"/fronts/prevention/"}],"technology":[{"id":"cancer-treatment-bone-loss","kind":"technology","name":"Bone loss caused by cancer treatment, and what rebuilds it","route":"/technologies/cancer-treatment-bone-loss/"},{"id":"chemoprevention","kind":"technology","name":"Chemoprevention & risk-reducing surgery","route":"/technologies/chemoprevention/"}],"drug":[{"id":"bevacizumab","kind":"drug","name":"Bevacizumab","route":"/drugs/bevacizumab/"},{"id":"folfox","kind":"drug","name":"FOLFOX (5-FU, leucovorin, oxaliplatin)","route":"/drugs/folfox/"}],"term":[{"id":"unproven-diet-claims","kind":"term","name":"Unproven diet claims (alkaline, juice, 'anti-cancer' diets)","route":"/terms/unproven-diet-claims/"}],"trial":[{"id":"vital","kind":"trial","name":"VITAL (VITamin D and OmegA-3 TriaL)","route":"/trials/vital/"}],"bottleneck":[{"id":"b-negative-results","kind":"bottleneck","name":"Failures are hidden","route":"/bottlenecks/b-negative-results/"},{"id":"b-misinformation","kind":"bottleneck","name":"Misinformation and unproven therapies","route":"/bottlenecks/b-misinformation/"}],"paper":[{"id":"paper-ng-jama","kind":"paper","name":"Effect of High-Dose vs Standard-Dose Vitamin D3 Supplementation on Progression-Free Survival Among Patients With Advanced or Metastatic Colorectal Cancer: The SUNSHINE Randomized Clinical Trial","route":"/key-papers/paper-ng-jama/"},{"id":"paper-manson-n-engl-j-med","kind":"paper","name":"Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease","route":"/key-papers/paper-manson-n-engl-j-med/"}],"roadmap":[{"id":"nutrition-lifestyle-roadmap","kind":"roadmap","name":"Diet, exercise and lifestyle roadmap: causes established → interventions that disappointed → exercise proven as treatment","route":"/roadmaps/nutrition-lifestyle-roadmap/"}]}}