Fish Oil and Vitamin D Supplementation Not Beneficial

A nationwide, randomized, placebo-controlled trial revealed that daily supplementation with high-dose vitamin D or n-3 fatty acids for 5 years among initially healthy adults in the US did not reduce the incidence of cancer or the incidence of major cardiovascular events. The trial included 25,871 participants (5106 black, ages >/=50 years for men and >/=55 years for women). Marine n−3 (i.e. omega-3) fatty acids were supplemented at a dose of 1 g per day and vitamin D3 (cholecalciferol) was supplemented at a dose of 2000 IU per day. During a median follow-up of 5.3 years, cancer was diagnosed in 793 participants in the vitamin D group and 824 in the placebo group; hazard ratio (HR), 0.96. A major cardiovascular event occurred in 396 participants in the vitamin D group and 409 in the placebo group; HR, 0.97. A major cardiovascular event occurred in 386 participants in the n−3 group and in 419 in the placebo group; HR, 0.92 (HR for total myocardial infarction, 0.72 in the analyses of key secondary end points). Invasive cancer was diagnosed in 820 participants in the n−3 group and in 797 in the placebo group; HR, 1.03. No excess risks of bleeding, hypercalcemia or other serious adverse events were observed. The disappointing findings filled some knowledge gaps in a diverse U.S. cohort. Source: https://www.nejm.org/