Ginger is a great supplement that when taken can help to assimilate protein better in the body. You can buy in it capsule form or simply eat the real thing. Ginger is also great for cleansing the mouth of germs. If you consume enough of it you will feel your mouth burn.
I used to (and will start it again) mix 2 apples with a small chunk of ginger and some fruit punch Crystal Lite. It's a great way to get in some added fiber and nutrients from the apples. I notice that when I eat ginger on a regular basis like this that I don't seem to get colds.
I have a friend whose mother swears by preparing a fresh tea made from freshly chopped ginger and sliced lemons to knock out a cold before it gets a hold of you. I think it does help.
Oh and I love garlic and onions too.