Mayo Clinic
Mayo Clinic: Vitamin and Mineral Supplements
This site from the MayoClinic.com contains an article entitled, "Using vitamin and mineral supplements wisely". Focuses on the right balance of minerals and vitamins, but shows the benefits of whole foods as well.
Harvard University
Harvard School of Public Health: The Nutrition Source: Fiber
Why is fiber important to our diets? How can we get the fiber we need from the food we eat? In addition to answering the above questions, this website also describes the diseases and disorders we can avoid by eating fiber-rich foods.