What Are Essential Nutrients?

The list of nutrients includes hundreds of substances and list seems to keep getting longer. However, not all of the nutrients are deemed essential. Essential nutrients are those nutrients that are absolutely vital and are not made in the body either at all or in sufficient quantities to meet our needs. These essential nutrients must be in the foods we eat (or supplemented) and in sufficient quantities, otherwise signs of deficiency can develop over time. Essential nutrients can be grouped together based on general similarities, such as those that provide energy (carbohydrates, proteins, and fats), vitamins, minerals, and water. This is presented in Table 3.1
 

There are more than forty essential nutrients that have to be part of our diet and at certain levels to prevent deficiency.
 

We can reinforce our understanding of the difference between nutrients and essential nutrients with an example. Glycine is an amino acid, which is absolutely necessary to make proteins in our cells. We have the ability to make ample glycine and therefore, theoretically, it does not need to be part of our diet. However, our body will gladly put the glycine we eat to work, so it is indeed a nutrient; it is just not considered an essential nutrient. Said another way, if glycine was lacking from our diet, it is unlikely that deficiency signs would develop because we can make plenty of it in our body.