Updated on 7/29/2005
My first choice would be astragalus, the root of a plant native to northern China and Inner Mongolia. In contemporary Chinese medicine astragalus is a chief component of fu zheng therapy, a combination herbal treatment designed to restore immune function in patients undergoing chemotherapy and radiation. Research in China has demonstrated increased survival when patients receive both herbal and conventional cancer therapies, and several studies in the west confirm astragalus' anti-viral and immune-boosting effects. You can buy astragalus preparations in most health food stores. Children can take the same dose as adults, usually two capsules or tablets twice a day unless the product directs otherwise. You can continue treatment with astragalus indefinitely.
I also would suggest Asian mushrooms for their immune enhancing effects. It's best to use a combination product containing extracts of a number of active species, such as maitake, reishi, cordyceps, and others.
You also might consider introducing your child to mind-body techniques to enhance immune function and reduce side effects of chemotherapy. Children do particularly well with visualization, guided imagery and hypnotherapy.
Andrew Weil, M.D.