ABSTRACT
Essential nutrients are organic and inorganic substances required to sustain life. They are used for growth, maintenance, tissue repair, and reproduction, and foods are the vehicles for them. Different organisms require different nutrients for their existence. To sustain life and maintain health, dietary intakes of nutrients must meet certain minimal levels. An individual food may contain only a few nutrients, or it may supply many. However, no single food provides all the nutrients in amounts and proportions necessary for adequate health. If the total diet supplies all the essential nutrients, the cells and body organs can synthesize many thousands of additional metabolically important substances.
