(DY-uh-TAYR-ee SUH-pleh-ment) 
A product that is added to the diet. A dietary supplement is taken by mouth and usually contains one or more dietary ingredients. Examples of dietary ingredients include vitamins, minerals, herbs, amino acids, and enzymes. A person should talk with their health care provider before taking dietary supplements, as some may have side effects or interact with other dietary supplements and medicines. Also called nutritional supplement.