Christine,

I had Hodgkins Disease (Lymphoma) and I used MGN3 from (http://www.lanelabs.com) to help boost my immune system. I also use Liquid Echinacea Vitamin C from (http://www.integrativeinc.com/products/display.asp?id=1145&cpmid=1071) but I purchase this from my Naturopath.
Some mushrooms are very good immune system boosters:
Maitake, Cordyceps and Shiitake. Check (http://www.mushroomscience.com/).

Foods to avoid (that hinder the immune system): Sugar, any food with hydrogenated oils, peanuts in any form (even organic), alcohol

Try to eat fresh organic food. You can buy organic food at (http://www.wholefoods.com/) or try to buy locally. Try to use non-toxic cleaners (http://www.seventhgeneration.com/) to create a less toxic environment.

I hope this helps.

Add fresh juices if he isn't already. Two recipes I have for immune building properties are: (these are taken from the Juiceman Jr. recipe book)

1st recipe:
2 tomatoes
1 handful of parsley
2 Celery stalks
1/2 cucumber
1/8 onion


2nd recipe:
4 carrots
3 sprigs parsley
2 Celery stalks
2 cloves garlic

There is also a blood regenerator recipe:

6 carrots
6 spinach leaves
4 lettuce leaves (not iceberg)
1/2 beet
4 sprigs parsley

Hope that helps some. Take care.