It is common knowledge that your body needs a daily ration of various vitamins and minerals (at least I hope it is common knowledge) to maintain health and function! The problem is that most people don't know the specifics on these vitamins and minerals and so don't realize their significance, and ultimately the body's true nutritional needs are not fully met (if at all).
Here is a handy pdf found on Women's Running Magazine. This great article lists all the major vitamins and minerals and where to find them...in your food!
Download it, read it, and take it to the grocery store for your next shopping run!