The VITamin D and OmegA 3 TriaL (VITAL) rationale and design of a large randomized controlled trial of vitamin D and marine omega 3 fatty acid supplements for the primary prevention of cancer and cardiovascular disease.
Data from laboratory studies, observational research, and/or secondary prevention trials suggest that vitamin D and marine omega 3 fatty acids may reduce risk for cancer or cardiovascular disease (CVD) but primary prevention trials with adequate dosing in general populations (i.e. unselected for disease risk) are lacking. The ongoing VITamin D and OmegA 3 TriaL (VITAL) is a large randomized, double blind, placebo controlled, 2 x 2 factorial trial of vitamin D (in the form of vitamin D(3) [cholecalciferol] 2000 IU/day) and marine omega 3 fatty acid (Omacor fish oil, eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA] 1g/day) supplements in the primary prevention of cancer and CVD among a multi ethnic population of 20,000 U.S. men aged 50 and women aged 55. The mean treatment period will be 5 years. Baseline blood samples will be collected in at least 16,000 participants, with follow up blood collection in about 6000 participants. Yearly follow up questionnaires will assess treatment compliance (plasma biomarker measures will also assess compliance in a random sample of participants) use of non study drugs or supplements, occurrence of endpoints, and cancer and vascular risk factors. Self reported endpoints will be confirmed by medical record review by physicians blinded to treatment assignment, and deaths will be ascertained through national registries and other sources. Ancillary studies will investigate whether these agents affect risk for diabetes and glucose intolerance; hypertension; cognitive decline; depression; osteoporosis and fracture; physical disability and falls; asthma and other respiratory diseases; infections; and rheumatoid arthritis, systemic lupus erythematosus, thyroid diseases, and other autoimmune disorders.
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