VITAL Study - Autoimmune Prevention Requires Continued Supplements Save

In the 2 years that followed the termination of the VITAL study, the preventative effect of vitamin D on incident autoimmune disease disappeared with supplement discontinuation; but n-3 fatty acid treated individuals had a sustained benefit in reducing the risk of autoimmune disease.

VITAL was reported in 2021 as a 5.3 year randomized, double-blind, placebo-controlled trial comparing the benefits of VITamin D vs. OmegA-3 TriaL (VITAL). The VITAL study was originally performed to assess effects on cancer and cardiovascular outcomes, but failed to do so in results previously published in the NEJM. 

At ACR 2021, a significant autoimmune preventative effect was seen for vitamin D (2000 IU qd) (HR 0.78, 95% CI 0.61-0.99), but not for Omega-3(n-3) fatty acid supplementation (HR 0.85, 0.67-1.08).

The current post-intervention analysis followed patients for an additional 2 years. A total of 21,592 participants (83.5%) were followed observationally for two more years. Incident autoimmune disease (AD) occurred 514 participants (236 since prior report).

At 7 years, a significant reduction in AD was seen for those randomized to n-3 fatty acids vs. placebo (HR 0.83; 0.70-0.99).  Conversely, those randomized to vitamin D were no longer protected from incident AD compared to PBO (HR 0.98; 0.83-1.17). 

With the end of the VITAL study and discontinuation of supplements, this 2 year extention observational study suggests that autoimmune disease protection may require continuous vitamin D supplementation, while the  beneficial  effects  of  n-3  fatty  acids may  be  prolonged for at least two years after discontinuation.