5 NAD+ Precursors: Where Can You Find Them?

NAD+ is a coenzyme that plays an important role in cellular energy metabolism. NAD+ levels decrease with age, which is associated with many diseases such as Alzheimer's, Parkinson's, and aging. Therefore, there is great interest in supplementing NAD+ through its precursors. This article will introduce the 5 most common NAD+ precursors, their natural sources, and the most effective ways to supplement.

What Is NAD+?

NAD+ (Nicotinamide adenine dinucleotide) is an important coenzyme required for energy production through cellular respiration. In the electron transport chain, NAD+ acts as a hydrogen acceptor that helps convert nutrients into ATP. Specifically, NAD+ works by accepting electrons from other molecules and converting them into NADH. NADH then transfers these electrons to the electron transport chain, leading to ATP production [1].

In addition, NAD+ also plays an important role in DNA repair, and cell signaling and participates in other essential biological processes in the body:

• Energy production: NAD+ plays a key role in the electron transport chain to create ATP. NAD+ is involved in converting energy from food into ATP through oxidation in cells. It acts as an intermediate in this process, helping the body metabolize more efficiently.
• DNA repair: NAD+ participates in the process of repairing DNA damage, helping to prevent aging, improve blood circulation, increase brain function, and protect the body from disease. In particular, the main function of NAD+ is the ability to prevent aging and increase the overall lifespan of humans.
• Helps Enzymes Work Efficiently: NAD+ normally acts as a coenzyme for many important enzymes in the body. It helps enzymes function efficiently in many biological processes, including metabolism and ATP production.
• Oxidation: NAD+ is involved in oxidation and reduction processes in the body. This is involved in metabolism, energy production, and maintaining energy balance in cells.

What Are NAD+ Precursors?

NAD+ precursors are compounds that can be converted into NAD+ in the body. Supplementing these precursors helps increase endogenous NAD+ levels. Because NAD+ in the human body naturally decreases with age. Therefore, supplementing NAD+ precursors brings many health benefits, including anti-aging, and preventing common diseases in the elderly such as Alzheimer's, and Parkinson's,... [2]

5 NAD+ Precursors And Where To Find Them?

Nicotinic Acid (NA)

Nicotinic Acid (NA), also known as niacin or vitamin B3, is one of the most important precursors for NAD+ synthesis in the body. The main mechanism for the conversion from NA to NAD+ involves intermediate metabolic steps.

When NA is absorbed into the body, it is converted to NAD+ via the Preiss-Handler pathway. During this process, NA is converted to Nicotinate Mononucleotide (NaMN), then to Nicotinate Adenine Dinucleotide (NaAD), and finally to NAD+ [3].

Foods rich in Nicotinic Acid to supplement the body include:

• Chicken, beef, fish: Especially tuna, salmon, white meat chicken.
• Whole grains: Barley, whole wheat, oats.
• Seeds: Sunflower seeds, pumpkin seeds.
• Beans: Peanuts, green beans, black beans.
• Mushrooms: Mushrooms especially button mushrooms.

Nicotinamide Riboside (NR)

Nicotinamide Riboside (NR) is also a form of vitamin B3 and is one of the precursors of NAD+ in the body. NR is considered an effective source of NAD+ supplementation due to its ability to be easily absorbed through the digestive tract and rapidly converted to NAD+ in cells [3].

When NR is absorbed into the body, it undergoes a series of biochemical reactions to be converted into NAD+. This process includes the following main steps:

• Absorption of NR through the digestive tract: NR is well absorbed through the intestine and transported into the blood, then moves to cells throughout the body.
• Phosphorylation of NR to Nicotinamide Mononucleotide (NMN): Inside the cell, NR is converted to Nicotinamide Mononucleotide by the enzyme Nicotinamide Riboside Kinase (NRK). This is the first important step in the pathway for NAD+ synthesis from NR.
• Conversion of NMN to NAD+: NMN is then converted to NAD+ by the enzyme Nicotinamide Mononucleotide Adenylyltransferase (NMNAT).

Foods rich in NR to supplement the body include:

• Milk and dairy products: Soy milk, yogurt, cheese.
• Fish: Especially salmon, and sardines.
• Turkey: A typical rich source of NR.

Nicotinamide (NAM)

When Nicotinamide (NAM) is absorbed into the body, it undergoes a series of enzymatic reactions to be converted to NAD+:

• Nicotinamide Absorption Through Gastrointestinal Tract: Nicotinamide is efficiently absorbed through the small intestine and then distributed into the bloodstream to travel to cells throughout the body.
• Conversion of NAM to NMN: Inside the cell, NAM is converted to Nicotinamide Mononucleotide (NMN) via the enzyme Nicotinamide Phosphoribosyltransferase (NAMPT). This reaction involves the conjugation of NAM with 5-phosphoribosyl-1-pyrophosphate (PRPP), producing NMN.
• Conversion of NMN to NAD+: Similar to the mechanism analyzed above.

NAM can be supplemented into the body through foods such as:

• Meat and poultry: Chicken (especially the breast), lean beef, and lean pork (especially the loin) are good sources of NAM.
• Fish and seafood: Tuna, salmon, and sardines are all foods rich in omega-3s and NAM along with other essential nutrients.
• Barley, whole wheat, and oats: Rich in vitamin B3 in the form of NAM.

Nicotinamide Mononucleotide (NMN)

Nicotinamide Mononucleotide is one of the important precursors of NAD+. When supplemented into the body, NMN is rapidly converted to NAD+, helping to maintain NAD+ levels in cells and supporting many important biological functions [4].

The conversion of NMN to NAD+ occurs in the following steps:

• NMN absorption through the digestive tract: NMN is well absorbed through the small intestine and transported into the blood. Similar to other NAD+ precursors, NMN is also distributed to cells throughout the body.
• NMN Transport and Cells: NMN can be transported directly into cells through several mechanisms, including specialized transport channels such as the NMN transporter found in the cell membrane. This allows NMN to enter cells directly without having to be converted to another form before entering the cell.
• Conversion of NMN to NAD+: Once inside the cell, NMN is converted to NAD+ by the enzyme Nicotinamide Mononucleotide Adenylyltransferase (NMNAT). NMNAT catalyzes this reaction in its three isoforms: NMNAT1 (in the cell nucleus), NMNAT2 (in the Golgi and neurons), and NMNAT3 (in the mitochondria).

• Broccoli, spinach, cabbage: Dark green vegetables are rich in NMN.
• Avocado: In addition to its NMN content, avocados are also rich in good fats and fiber.
• Edamame: Known to be a rich source of NMN and vegetable protein, especially good for vegetarians.

Tryptophan (TRP)

Unlike the previous four precursors of NAD+, Tryptophan (TRP) is an essential amino acid in the body. In addition to being a precursor for Serotonin and Melatonin, TRP is also an important precursor in the synthesis of NAD+ in the body. TRP is converted to NAD+ via the Kynurenine pathway from sources other than direct NAD+. This pathway converts TRP to NAD+ through a complex series of enzymatic reactions [5].

Tryptophan is an essential amino acid, meaning the body cannot synthesize it, and must be supplemented through the diet. Here are foods rich in Tryptophan:

• Chicken (especially turkey), beef, and pork: These lean meats contain significant amounts of tryptophan.
• Salmon, tuna, shrimp, and scallops: Provide Tryptophan and good fatty acids along with many important minerals.
• Cow's milk, goat's milk, cheddar, and mozzarella cheese: These are also foods that contain high amounts of tryptophan and protein.
• Brown rice and whole wheat: Not only do they contain TRP, they also contain many health-promoting B vitamins.

What Is the Best Way To Supplement NAD+?

As analyzed and mentioned above, the amount of NAD+ in the body will gradually decrease with age and time, causing various health effects, including Alzheimer's disease, Parkinson's disease, poor blood circulation, reduced brain function,... Therefore, supplementing NAD+ for the body is extremely necessary.

Methods to increase NAD+ levels in the body mainly revolve around:

• Use supplements: NAD+ supplements, as well as NAD+ precursors, have been studied and proven to effectively increase NAD+ levels in the body. However, you should be careful to choose a reputable brand and consult your doctor for specific dosages and to ensure health safety.
• Balanced diet: By adding the above NAD+-rich foods such as milk, white meat, beans, and nuts, you can naturally increase NAD+ levels in your body, while also helping you improve your overall health [6].
• Exercise: Regular exercise increases NAD+ levels and improves mitochondrial function.

Conclusion

NAD+ plays an important role in energy metabolism and anti-aging. Supplementing NAD+ through NAD+ precursors brings many health benefits. Hopefully, the above article provides you with information related to NAD+ precursors, how they work, and sources of NAD+ precursors for the body. It should be noted that before using any supplement, you should consult your doctor for appropriate advice.