The FDA developed it's nutritional guidelines to prevent nutrition related diseases such as scurvy back in the 1800's and has NEVER updated most of them. They are also very much financially backed by the AMA and by Drug Companies whose main focus is on corrective rather than preventative medicine. Therefore, I don't really trust much of what the FDA has to say about what I sould and shouldn't eat. I highly reccommend that anyone who is interested in finding out the truth about nutrients (vitamins and minerals) read a book called "What Your Doctor Doesn't Know About Nutritional Medicine May Be Killing You" by Dr. Ray Strand. He outlines how optimizing levels of key nutrients can help to prevent and in some cases correct many dibilitating diseases such as diabetes and cancer.
Yes, and Dr. Strand believes in limiting the consumption of mercury rich fish such as low quality tuna and swordfish
Another good book for those who like Dr Strand one is "Food Is Your Best Medice" by Dr. Henry Bieler