Question: Are there any supplements I can take to help boost my immune system so I don't get frequent colds?
Answer: I wish I knew of something that would boost your immune system to make it so you were less likely to get colds. I can tell you what I do in my attempt to get less frequent colds. And what I do is I wash my hands a lot. And I particularly wash my hands before I pick my nose or rub my eye, because that's frequently the way in which I inoculate myself with a virus.
Does soap and water count as a natural supplement? The answer is no. I don't know of something you can take to boost the immune system to ward off the virus that you inoculate yourself with. So, it's okay to take them if you think they might be helpful, but I know of no evidence that this would benefit you.