Sources I used to make this chart:
http://www.livestrong.com/article/349163-berries-that-build-the-immune-system/
http://www.webmd.com/cold-and-flu/ss/slideshow-immune-foods
http://www.everydayhealth.com/cold-flu-pictures/top-immune-boosting-foods-to-keep-you-healthy.aspx#/slide-10
