Effect of Vitamin D and Omega-3 Supplements on Systemic Inflammation

In this issue of Clinical Chemistry, Costenbader et al. (1) report on the enticing proposition that supplementation with omega-3 fatty acids combined with vitamin D has a beneficial effect on systemic inflammation. Systemic inflammation is an underlying component of many chronic diseases such as cardiovascular disease and type 2 diabetes. Higher levels of inflammation have been observed in individuals with low 25 hydroxyvitamin D status (2, 3) and also in association with low fish intake or fatty acid status (4). In theory, combining these 2 nutrients could maximize their antiinflammatory effects through synergistic actions on pathways of inflammation. Costenbader et al. (1) report the findings of a substudy (n = 1561) of the VITAL (VITamin D and OmegA-3 Trial) population-based randomized controlled, factorial trial (total sample size n = 24310). The target population was men older than 50 years of age and women over 55 years of age and the intervention dosage used in the trial was 2000 IU vitamin D per day and/or 1 g omega-3 fatty acids per day for 1 year vs placebo. Inflammatory biomarkers of interest were C-reactive protein, interleukin-6, and tumor necrosis factor-receptor 2. The main finding of this VITAL substudy was that neither vitamin D nor omega-3 reduced systemic inflammation …