Picking up on the immune system, Omega Man, have you seen this?
http://www.littleherbal-internationa...log/Simba.html
There's also a page about the immune system on the site.

You may also be interested in RSSL News. I subscribe to the Food e-Newsletter and it can be quite enlightening.
Coincidentally, one of the May editions carried this story about mutlivitamin use and "lack of positive impact on health"...!
See: http://search.rssl.com/cgi-bin/MsmGo...S+multivitamin+

As with all such information, I think you have to keep a bit of a sceptical mind - you shouldn't necessarily believe or follow all the advice. Otherwise there'd be nothing "safe" to eat out there!