Macronutrients in the diet provide building blocks for synthesis and sources of metabolic energy. Essential nutrients are those that must be provided in the diet because the body cannot make them. Proteins are the source of essential amino acids and nitrogen. Complete proteins have all the essential amino acids. Some fats (triglycerides) provide the essential fatty acids. Along with carbohydrates, they are primary sources of metabolic energy.
The minerals calcium, phosphorus, potassium, sulfur, sodium, chlorine, and magnesium are also needed in relatively large quantities to support growth and metabolism. Micronutrients are required in only small quantities and include the vitamins, other minerals, and possibly some phytochemicals from plants.
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