The prestigious British Medical Journal recently published a study that got little attention from Mainstream Media, probably because it wasn't about getting the COVID-19 vaccine. The study showed that four dietary supplements significantly reduce COVID-19 infection risk.



Using an app developed by Zoe Global, in partnership with King’s College London, Massachusetts General Hospital, Lund University, Sweden, and Uppsala University, Sweden, researchers reviewed data from more than 400,000 users.



To summarize their findings:




In the largest observational study on SARS-CoV-2 infection and dietary supplement use to date on over 400,000 app users from three different countries, we show a significant association between users of omega-3 fatty acid, probiotic, multivitamin or vitamin D supplements and lower risk of testing positive for infection with SARS-CoV-2.
Louca P, et al.



Interestingly, supplement use seemed to be more effective in women than men in relation to COVID-19.



What makes these supplements especially effective?





Vitamin D



One of the many health benefits of vitamin D is its impact on the immune system. 



Health care providers have known for decades that low vitamin D levels increase the risk of the flu and other infections. Vitamin D affects the function of T cells and B cells.



It’s no surprise, then, that low vitamin D levels could increase the risk of COVID-19. In the BMJ study, vitamin D supplementation lowered COVID-19 risk by 9% for United Kingdom participants and by 24% for those in the United States.



Another new study, published in The Lancet, also affirmed the protective effects of vitamin D supplementation.




In summary, this updated meta-analysis of data from RCTs of vitamin D supplementation for the prevention of ARIs showed a significant overall protective effect of this intervention compared with a placebo control.
Joliffe DA, et al.



Multivitamins



Though I’m a major advocate for multivitamin use, health care practitioners often question the health benefits of multivitamins. Because they include multiple ingredients, and the supplement market includes a wide range of qualities, the research on multivitamins isn’t as in-depth as that of the individual ingredients.



However, there’s no doubt that most people don’t get enough of most micronutrients for optimal health. Any micronutrient deficiency has the potential to interfere with immune function, but inadequate zinc, or vitamins A, C, D, and E can all increase the risk of viral infection.



In the BMJ study, multivitamin use lowered COVID-19 infection risk by 13% for those in the U.K., and 12% for those in the U.S.



Read also: The Best Multivitamins for Men and Women.



Omega-3 Fatty Acids (Fish Oil)



You might be surprised to see fish oil included in this list. When most people think of fish oil health benefits, they think of heart health, fat loss, brain function, and possibly muscle growth. 



Omega-3 fatty acids help support a normal inflammatory response, and inflammation plays a significant role in the immune process.



That said, it’s unclear exactly how fish oil reduces SARS-CoV-2 infection, but it does.



The data from the BMJ shows fish oil supplementation lowers COVID-19 risk in the United States by 21% and in the United Kingdom by 12%.



Probiotics



It’s often said that “70% of your immune system lies in your gut.” Whether that’s an accurate percentage or not, the point is that your gut health plays a crucial role in immune function.



That doesn’t mean your gut only protects you from pathogens that reach your gut. In reality, the bacteria in your intestines produce metabolites and other compounds that enhance immune function throughout the body.



In fact, research shows that the balance of good and bad bacteria in the gut impacts the function of immune cells even in the lungs.



Alveolar macrophages act as patrols in the lung tissues, causing an immune response when they encounter pathog...