“Vitamin D and Fish Oil of Little Benefit in Heart Disease, Cancer”
More research is showing no significant benefit from vitamin D supplementation for the prevention of cardiovascular disease (CVD) or cancer and little benefit from omega-3 supplements. The Vitamin D and Omega-3 Trial (VITAL) is one of the largest randomized, placebo-controlled trials to examine these associations. The study comprised almost 26,000 participants. The two primary outcome measures were invasive cancer of any type and major CVD events, which was a composite of stroke, myocardial infarction (MI), and CVD-related death. Neither the participants who received vitamin D3 nor those who received 1 g of marine n-3 fatty acids (omega-3) per day showed a significantly lower incidence of either outcome over 5 years of follow-up. However, there was a 28% reduction in risk for myocardial infarction (MI) alone in the full group receiving omega-3 and a 77% reduction in MI risk among black participants in the omega-3 group. This may point to a very promising approach to reducing coronary risk among African Americans. But overall the results were not impressive with any of the primary findings and only showed marginal benefits in “sub-analyses or in secondary endpoints,” which are not reliable scientific evidence of benefit. Importantly, no significant adverse events occurred with either agent, including no increased risk for hypercalcemia with vitamin D and no increased risk for bleeding with omega-3. Jane Armitage, MD, University of Oxford, United Kingdom, noted that although this was a well-conducted and well-powered study with an ethnically diverse population and good follow-up, “it was robustly negative” overall.
