There is nothing "natural" about a lot of things. There is nothing natural about wearing clothes, driving a car, wiping your ass with toilet paper, or communicating over the internet. Yet almost everyone does those things. What is considered "natural" varies from person to person. Vitamins or any supplement/pill can never be completely natural since it needs to be manufactured. This isn't to say that all vitamins are unnatural in that they contain artificial or synthetic ingredients, because I don't take cheap vitamins, and I don't advise that people do. We could argue semantics all day, but that never gets anywhere.