NUTRIENT Indrotuction Macronutrients Micronutrients Essential nutrients Amino acids Fatty acids Vitamins and vitamers Minerals Choline Conditionally essential Non-essential Non-nutrients Deficiencies and toxicity A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals , plants , fungi and protists . Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures such as hair , scales , feathers , or exoskeletons . Some nutrients can be metabolically converted into smaller molecules in the process of releasing energy such as for carbohydrates , lipids , proteins and fer...