Marian Nestle has written a great book called What to Eat. It is probably one of the best Health Food information books I have ever read.
I love what it says about vitamins, and herbal supplements p. 466-477. The whole book is really amazing! She talks about what imitation crab meat really is..what it goes through to become that, also about why salmon is pink...its really a book everyone should read. I could go on and on about the great topics she covers, but you should just read it, buy it or get it at the library...you may want to buy it, as I go back to it often.
If you want to see the book go to http://www.whattoeatbook.com/ Its her blog.
I like to read and when I find something good, I like to blab about it.