The molecular basis of nutrition refers to the understanding of how nutrients affect biological processes at the molecular level, including gene expression, enzyme activity, and cell signalling. This area of research aims to uncover how specific nutrients can influence metabolic pathways and overall health.

Orthomolecular nutrition is a form of alternative medicine that focuses on maintaining health through the optimal intake of nutrients, such as vitamins, minerals, amino acids, and other essential compounds. The term "orthomolecular" means "the right molecules in the right amounts," emphasizing the use of naturally occurring substances in the body to prevent and treat disease.