Vitamin D and Omega-3: Exploring their Role in Autoimmune Disease Prevention

In our last newsletter, we basked in the warm glow of the potential benefits of vitamin D for autoimmunity. Amidst the array of studies highlighting its advantages, the VITAL study shines brightly. It provides evidence that taking vitamin D for five years among older US adults could potentially lower the occurrence of autoimmune diseases. Today, let's step into the full sunlight of this research and soak up its revelations about the vital role of vitamin D in managing autoimmune conditions!

Background

The VITamin D and OmegA-3 TriaL (VITAL) was initially designed to investigate how daily supplementation of vitamin D and omega-3 fatty acids could potentially prevent cancer, heart attack, or stroke among a group of nearly 26,000 American adults. These participants, with an average age of 67.1 years, were followed closely for 5.3 years. The participants consisted of 12,786 men aged 50 years or older and 13,085 women aged 55 years or older. Employing a two-by-two factorial design, individuals were randomly assigned into four distinct groups:

• Group 1: Received both vitamin D3 (2000 IU) and marine omega-3 fatty acids (1 g containing 460 mg of EPA and 380 mg of DHA)

• Group 2: Received vitamin D3 (2000 IU) and a placebo for marine omega-3 fatty acids

• Group 3: Received marine omega-3 fatty acids (1 g) and a placebo for vitamin D3

• Group 4: Received placebos for both vitamin D3 and marine omega-3 fatty acids

This approach allowed researchers to delve deeply into the effects of each supplement alone and in combination, offering a nuanced understanding of their impact on the health outcomes studied. 

VITAL and Autoimmune Diseases

While VITAL primarily centered on cancer and cardiovascular disease prevention, it branched into various additional studies, including the occurrence of autoimmune diseases. The study, Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial published in 2022 in The British Medical Journal aimed to explore whether supplementing with vitamin D and marine-derived omega-3 fatty acids could potentially lower the risk of developing autoimmune conditions. Participants reported any new autoimmune diseases they experienced, which were then confirmed through extensive reviews of their medical records.

Objective

The main focus of the study was to track the development of autoimmune diseases like rheumatoid arthritis, thyroid disease, or psoriasis during the study period. The aim was to gauge how autoimmune diseases emerged among the participants and to assess how the supplements affected their prevention.

Results

Those who took vitamin D had fewer confirmed autoimmune diseases than those who didn't. Vitamin D seemed to offer defense against these diseases over five years, with stronger effects seen after two years of supplementation.

For the group taking omega-3 fatty acids, it didn't show a statistically significant difference in the number of confirmed autoimmune diseases compared to the group that didn't take it.

When researchers looked at different combinations of vitamin D and omega-3 fatty acids, those who took both seemed to have the lowest number of confirmed autoimmune diseases. Taking only vitamin D or only omega-3 fatty acids also showed some decrease, but not as much as when they were taken together.

Conclusions

The outcomes from this trial revealed a 22% reduction in confirmed autoimmune diseases with five years of vitamin D supplementation, whether accompanied by omega-3 fatty acids or not—a statistically significant finding. However, the sole use of omega-3 fatty acid supplements, although it decreased the occurrence of autoimmune disease by 15%, did not exhibit a statistically significant decrease in autoimmune disease incidence. When omega-3 fatty acids were combined with vitamin D, the incidence of autoimmune disease was reduced by about 30% compared to the placebo group. Overall, both the vitamin D and omega-3 fatty acid groups had better results compared to those who didn't take these supplements at all.

When the researchers looked at the effects of the treatments without considering the first two years of the study, they found that the group taking vitamin D had a notably lower number of confirmed autoimmune disease cases compared to the placebo group. This difference wasn't seen in the group taking omega-3 fatty acids.

The researchers noticed that the vitamin D treatment consistently showed better results in the last three years compared to the first two years. However, when they looked at the overall picture of the entire five-year study, they didn't find strong evidence that the treatment effects changed over time for either vitamin D or omega-3 fatty acids.

Implications for Autoimmune Diseases

The results of VITAL suggest that vitamin D supplementation could be a beneficial strategy for reducing the risk of developing autoimmune diseases. This could be particularly relevant for individuals who are at high risk of developing such diseases. However, since the study focused on older adults, the implications for younger individuals remain uncertain, warranting further research. While omega-3 fatty acid supplementation alone did not show a statistically significant reduction in autoimmune disease incidence, it did show a reduction when combined with vitamin D. This suggests that omega-3 fatty acids could potentially enhance the beneficial effects of vitamin D supplementation. These discoveries might pave the way for new, comprehensive strategies in both preventing and treating autoimmune diseases. Stay tuned for more breakthroughs on the horizon!

Take good care,
Rebecca

Further Resources

• Read the full study for an in-depth exploration of the findings

• Learn more about the VITAL study

Disclaimer: I am not a healthcare provider, and the information provided in this newsletter is intended for educational purposes only. The content shared here should not be used as a substitute for professional medical advice, diagnosis, or treatment. Always consult with your healthcare provider or physician for personalized guidance regarding any health concerns or medical conditions.