dietary supplement

dietary supplement A substance that can be added to the diet, usually in pill, liquid, or powder form, ostensibly to promote health. Dietary supplements range from natural weight-gain concoctions used by body-builders, to joint pain relievers, vitamins, herbs, minerals, and salts that claim health benefits. Many dietary supplements are harmless when taken as directed, and the health benefits of some have been substantiated. Dietary supplements can interact with prescription medications, and some are not suitable for people with certain medical conditions.