Out in our natural market, immunity is a hot topic. There are many different ways to increase and maintain your immune function. Most of your immune system lies in your gut, so keeping healthy GI tract is crucial to keeping you healthy.
Probiotics are a great way in accomplishing this. They are easily found in yogurt, Kefir, frozen yogurt, cereals and cheese. You can also take a supplement, usually called acidophilis.
Vitamin D is also very important in maintaining a healthy immune system. Most people that live in the midwest do not get enough Vitamin D from the sun (because we really only get great Vitamin D sun in June, July and August). Vitamin D sources are mainly milk and oily fish. So a supplement is a great choice! I recommend 2000 I.U. a day.
And finally, there are immune enhancing supplements that can also give you a boost. If you notice during certain times of the year that you get sick (change of seasons, allergies, winter colds) these are another great option, some examples are Immune Basics and Epicor.