Negative effects of vegetarianism

 This is going to be a speech, talking about negative effect of vegetarianism. Main audience will be high school and college students who have no nutrition background at all. Please use plain oral English only, no heavy academic vocabulary. The format doesn’t matter since it is a speech, but write a nice source page, standard MLA format, which I need to turn in later on. The sources needs to be good, if you get from internet, better to be .gov or .edu website, or from books, academic journals etc.