nutrient

nutrient Any substance that is required for the nourishment of an organism, providing a source of energy or structural components. In animals nutrients form part of the diet and include the major nutrients, i.e. carbohydrates, proteins (see also essential amino acid), and lipids (see also essential fatty acids), as well as vitamins and certain minerals (see essential element). Plant nutrients, derived from carbon dioxide in the atmosphere and water (containing minerals) absorbed from the soil by the roots, are divided into macronutrients and micronutrients.