Nutrition expert Daniel Gastelu has written the ultimate guidebook for anyone who wants to know what they're putting in their bodies before they "pop the cap" on any of today's dietary supplements. For the first time, readers interested in improving their health can finally make sense of the booming -- and confusing -- world of vitamins, minerals, herbs, metabolites, and other supplements. This extraordinary book gives an industry insider's view on what dietary supplements are, how they are made and regulated, why certain formulations are more effective than others, and what scientific research tells us is safe and effective, entry by entry.