There is a “D” in Covid-19. But can a lack of Vitamin D make you more susceptible to the Covid-19 coronavirus? Well, some studies have suggested this possibility. However, before you rush to the store and start hoarding Vitamin D supplements like they were toilet paper, let’s “D”-construct the currently available evidence.
If you think that Vitamin D only has to do with bone health, you may be wondering what it could possibly have to do with Covid-19. After all, you may have a bone to pick with the virus but its main effects don’t seem to be on your skeleton. Well, studies have shown that Vitamin D may affect different components of your immune system and its response to infection. It may help modulate your lymphocytes and inflammation-producing chemicals like cytokines that are important components of your immune response to invading viruses.
This could potentially, possibly, perhaps be relevant for Covid-19 because badness may result when your immune system overreacts to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2). As I’ve described previously for Forbes, since your immune system is not used to seeing the SARS-CoV2, your body’s defenses can act like someone experiencing something like sex for the first time. It can be a bit, ahem, quick on the trigger and start trying all kinds of random things, many of which don’t really work. Some of which may cause damage to the surroundings (your body, in the case of your immune response and your bedroom, in the case of sex). In some cases of Covid-19, the resulting “cytokine storm” can cause widespread damage to different organs and lead to death. Therefore, any way that your immune system can better regulate its own response could potentially be beneficial.
Back in 2017, the BMJ published a systematic review and meta-analysis of randomized, placebo controlled clinical trials that evaluated how Vitamin D supplementation may affect the risk of getting acute respiratory tract infections. The review returned 25 such trials. The combined results revealed that those who received Vitamin D supplementation had a 12% lower likelihood of getting an acute respiratory tract infection. Although the authors of this systematic review concluded that “Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall,” a letter to the BMJ warned that people shouldn’t go overboard with these recommendations, that taking too much Vitamin D has it’s risk too.