Nearly half of Americans use supplements--and many more are curious about them--yet questions abound. Will feverfew help my migraines? Are there any vitamins that will keep my skin clear? Does lysine really prevent cold sores? Are there herbs I can take to boost my mood? Are any of these things safe ? Mark Moyad, MD, MPH is the only physician in the United States who has an endowed position to study vitamins, minerals, herbs, and other supplements...