The modern science of nutrition, starting from its origins more than one century and a half ago, initially has been strictly confined to the concepts of dietary requirements. These included energy and single macronutrients, as well as micronutrients such as minerals, microelements, and vitamins. The main focus was the prevention and treatment of nutrient deficiency diseases, such as scurvy because of inadequate vitamin C intake. Instead, determining nutrient reference intake designed to promote optimal health and prevent chronic diseases across a diverse population group is a much more difficult question.