Nicotinamide Adenine Dinucleotide (NAD)
What is it?
Nicotinamide Adenine Dinucleotide or NAD is a molecule found in every living thing and in every cell of your body. It is imperative for life and has many functions to maintain cell balance, used as a cofactor in cellular metabolism, and in genome stability and replication, immunity, aging and disease.
Where does it come from?
NAD is produced from niacin, which is also known as vitamin B3, a water-soluble B vitamin, and tryptophan which is an amino acid (one of 20 other building blocks of protein). Both Niacin and tryptophan are found primarily in proteinaceous food sources such as meat, poultry, fish, legumes, nuts and various cereals (NIH., 2020).
Advancement in the appreciation of the biological functions and compartmentalization of NAD synthesizing and NAD consuming enzymes have resulted in the emergence of NAD+ metabolism as a foremost healing objective for age-related diseases.
Coenzymes in metabolism
As was previously mentioned, NAD has a pivotal role in metabolism, and it can be transformed into different structures to perform its various functions. For instance, it can be phosphorylated (a phosphorous atom is added to the molecule), or it can have electrons added or taken away (reduced or oxidized) from it so that it might perform these actions in cells. These metabolic roles include the metabolism of glucose or sugar, fatty acids, cholesterol, steroid synthesis, in folate metabolism and synthesis of deoxyribonucleotides (pivotal for DNA synthesis) to name a few. All these roles in metabolism allow us to harness energy from the food we eat and manufacture complex molecules needed for our cells to function properly (Gropper, S. S., Smith, J. L., & Groff, J. L., 2009).
Other cellular functions
Nicotinamide Adenine Dinucleotide also has a role in modifying proteins in enzymes that have certain roles in cell communication, immune function, cell signaling, transcription regulation (DNA replication for cell division), programmed cellular death and cell differentiation. They are even involved in a molecule called DNA polymerase, which is a DNA proofreading molecule that prevents mistakes from occurring during DNA transcription or replication, which promotes stability of the genetic material. NAD is also responsible for calcium mobilization, which is necessary for muscular contraction, neurotransmission, immune cell activation and even insulin release from the pancreas. In short, this molecule has an indispensable role in cellular regulation or homeostasis (Niacin., 2020) & (NIH., 2020).
Role in disease and aging
Considering the roles NAD has in metabolism of glucose, fatty acids and cholesterol, niacin has emerged as having a role in mitigating or controlling chronic diseases such as diabetes and cardiovascular disease. Additionally, some of the enzymes that NAD is a part of may even have a role in reducing cancer risk due to its role in genomic stability and regulation in cell differentiation and growth (Niacin., 2020).
Deficiencies are rare in the developed world and are primarily seen in developing countries where protein malnutrition is common, especially among vulnerable populations where growth and development is greater such as in babies, children, and pregnant women. Deficiency may also be present in those with alcoholism, or malabsorptive issues that can impair absorption. A deficiency of niacin results in a clinical deficiency called pellagra, and it is characterized by the 4 D’s- diarrhea (gastrointestinal distress), dermatitis (rash), dementia (neurological manifestations and cognitive dysfunction) and eventual death (Gropper, S. S., Smith, J. L., & Groff, J. L., 2009).
Referencing metabolism, nicotinamide adenine dinucleotide is involved in redox responses, transporting electrons from one reaction to another.
Gropper, S. S., Smith, J. L., & Groff, J. L. (2009). Advanced Nutrition and Human Metabolism (5th ed.). Belmont, CA: Wadsworth: Cengage.
Niacin. (2020, January 1). Retrieved from:
Office of Dietary Supplements - Niacin. (2020, March 26). Retrieved from https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/