Hopefully part 2 will contain a section about how Vitamin D regulates cytokine production in your lungs. Without enough vitamin d, your body over reacts to a respiratory illness by over producing cytokines, and then the patient has a much higher chance of dying.
There has to be additional evidence showing a decline in vitamin D levels over the past 20 years or so as we all got addicted to our devices, became narcissistic and anti social as a result of social media addiction, and largely stayed inside more than we used to. So we cut off our main source of vitamin D over time, and here we are...