Skimming the important bits, one of the headers reads:
> Vitamin D Works Better Than Flu Vaccine If Your Levels Are Low
The important part: "if your levels are low". Presumably, getting vaccinated and fixing your vitamin deficiency would be the best course of action.
This is a highly misleading article.
Edit: Furthermore, the OP appears to be posting multiple articles with the same propaganda and conspiracy theories, many of which are flagged/dead: https://news.ycombinator.com/submitted?id=ColanR