Could vitamin D be the cure to the common cold?

Cure?

No, but there is evidence that suggests it has the potential to lower your chances of getting sick and reduce the severity of sickness when you do.

Not quite a cure, but I’d say that’s pretty promising!

Pham et al. 2019 found as concentrations of vitamin D decreased, the odds of a acute respiratory tract infection increased (1). Notably they found that the risk increased the most when vitamin D concentrations dropped below 37.5nmol/L (15ng/mL). Beyond just the risk of infection, they found an even stronger association between vitamin D concentrations and the severity of infection!

If vitamin D concentrations are correlated with both risk and severity of infection, then you might expect to see benefit in supplementation …

Well Martineau et al. 2017 looked at exactly that! They concluded that “vitamin D supplementation is safe and protected against acute respiratory infection overall” (2). Interestingly they found it was much more effective to supplement on a daily or weekly basis than taking a large dose more infrequently.

Now I have personally found great benefit in supplementing with vitamin D and there is most definitely promising research showcasing the potential benefits of it. However, it’s also important to note there is research which has found little to no effect of vitamin D. So while I can recommend getting enough vitamin D, I can’t go as far as to guarantee that supplementing with it will eliminate your chances of getting sick entirely!

It should go without saying that the human body is very complex and there’ll generally be more factors at play than just a lack of one nutrient. Beyond vitamin D, it’ll always be important to make sure you’re getting enough sleep and exercise, not to mention all the other nutrients your body needs!