| 13-1 |  
 App 13-1 Ref. |  
  https://time.com/5825485/coronavirus-risk-factors/ 
 |  
 
  | 13-2 |  
 App 13-2 Ref. |  
  https://greekcitytimes.com/2020/06/23/stanford-university-epidemiologist-john-ioannidis-fatality-rate-of-covid-19-lower-than-initially-speculated/ 
 |  
 
  | 13-3 |  
 App 13-3 Ref. |  
  https://www.nature.com/articles/s41577-020-0331-4 
 |  
 
  | 13-4 |  
 App 13-4 Ref. Video + |  
  https://www.youtube.com/watch?v=WJLwjBmPKcM 
 |  
 
  | 13-5 |  
 App 13-5 Ref. + |  
  https://www.theatlantic.com/health/archive/2011/11/how-health-and-lifestyle-choices-can-change-your-genetic-make-up/247808/ 
 |  
 
  | 13-6 |  
 App 13-6 Ref. + |  
  https://blog.stridehealth.com/post/change-your-diet-change-your-genes 
 |  
 
  | 13-7 |  
 App 13-7 Ref. Video + |  
  https://www.youtube.com/watch?v=kp1bZEUgqVI 
 |  
 
  | 13-7 |  
 App 13-7 Ref. + |  
  https://hms.harvard.edu/news/what-grandma-ate 
 |  
 
  | 13-11 |  
 App 13-11 Ref. |  
  https://www.healthline.com/health-news/is-zinc-the-best-remedy-for-the-common-cold 
 |  
 
  | 13-12 |  
 App 13-12 Ref. + |  
  https://www.uchealth.org/today/zinc-could-help-diminish-extent-of-covid-19/ 
 |  
 
  | 13-13 |  
 App 13-13 Ref. |  
  https://www.healthline.com/nutrition/vitamin-c-coronavirus#1 
 |  
 
  | 13-14 |  
 App 13-14 Ref. + |  
  https://www.hunterpr.com/foodstudy_coronavirus/ 
 |  
 
  | 13-15 |  
 App 13-15 Ref. |  
  https://www.axios.com/coronavirus-vaccine-reality-tom-frieden-cdc-f99b71cb-f409-4774-9f65-41feca7158ef.html 
 |