What is NAD?

What is NAD+? How Does It Work?

NAD+ stands for nicotinamide adenine dinucleotide, and is a coenzyme, meaning it partners with enzymes throughout your body to keep essential processes running smoothly.

In fact, in contrast to popular belief, NAD+ isn't a vitamin itself. But it is made partly from vitamin B3. It exists in two forms: NAD+, the oxidized form, and NADH, the reduced form. 

NAD+ accepts electrons during metabolic reactions and becomes NADH in the process. NADH then donates those electrons to produce energy, converting back to NAD+ so the cycle can continue. This back-and-forth between the two forms is what keeps energy production running continuously in your cells.

Generally, NAD+ serves four major functions in the body, including:

• Converting food into energy that your cells can actually use
• Detecting and repairing damaged DNA
• Regulating metabolism and how genes are expressed
• Activating proteins associated with normal cellular functions

None of these processes happens in isolation. In other words, NAD+ doesn’t work alone; it facilitates each of these reactions by teaming up with specific enzymes across different cellular pathways.

‍

{{primary-cta}}

‍

Benefits of NAD: Energy Production & Metabolic Health

When you eat, your body breaks down glucose and fatty acids through glycolysis and the TCA (tricarboxylic acid) cycle. NAD+ acts as a key player in these reactions, accepting electrons and ferrying them to the mitochondria (your cells’ power plants) where they’re used to produce ATP, the energy currency your body runs on. 

Beyond energy, every day, your cells sustain DNA damage from normal wear and tear, environmental exposure, and the simple act of existing. Enzymes called PARPs (poly ADP-ribose polymerases) use NAD+ to detect that damage and coordinate the repair response. This process is essential for keeping your cells healthy and functioning correctly.

NAD+ also plays an important role in sirtuin activity. These seven proteins rely on NAD+ as a fuel to regulate metabolism, manage cellular stress, and support normal cellular function at the molecular level. Research suggests that when NAD+ is plentiful, sirtuins can perform their job effectively, and when levels fall, their activity declines as well.

Finally, NAD+ plays a broader role as a metabolic regulator. It helps govern redox homeostasis (the body’s balance between producing and eliminating reactive oxygen species and antioxidants), influences gene expression, and shapes how efficiently your metabolism responds to changes in nutrition, physical activity, and stress, including during exercise and fasting.

‍

Why Do NAD+ Levels Decline With Age?

NAD+ decline isn’t simply an unavoidable part of getting older; increasing evidence suggests that it’s driven by specific processes happening inside your cells. 

The first factor is increased demand for DNA repair. As you age, your cells accumulate more DNA damage, which triggers repair enzymes to work harder and for longer periods. These enzymes rely heavily on NAD+ to do their job, meaning more of your NAD+ supply gets directed toward repair, leaving less available for other functions like energy production.

The second factor is a slowdown in NAD+ production. Your body has a built-in system that continuously produces and recycles NAD+. With age, this system becomes less efficient, partly because a key enzyme involved in the process becomes less active. The result is that your body is using up NAD+ faster than it can replenish it.

The third factor is chronic low-grade inflammation. As we age, the body tends to experience a gradual increase in background inflammation. This triggers an enzyme called CD38 to become more active, and CD38 breaks down NAD+. 

Together, these three factors, higher demand, slower production, and increased breakdown, create a compounding effect that typically drives NAD+ levels down over time.

‍

How to Increase Your NAD Levels

The good news is that NAD+ levels aren’t entirely out of your control. A combination of lifestyle strategies and supplementation can help support healthy NAD+ production.

‍

Exercise

Regular physical activity is one of the most well-supported ways to maintain NAD+ naturally. Exercise has been shown to influence some age-related declines in NAD+ and stimulate sirtuin activation. It’s also one of the most accessible tools available, with no prescription required.

‍

Intermittent Fasting and Caloric Restriction

Both approaches trigger metabolic shifts that support NAD+ production. Animal studies show that fasting and caloric restriction increase blood NAD+ levels and activate sirtuins, making them compelling lifestyle strategies for those interested in metabolic health.

‍

NAD+ Supplements

For those looking to go further, several studied supplements may help support NAD+ levels. These include:

• NR (nicotinamide riboside) is a form of vitamin B3 and is a commonly studied NAD+ precursor. Inside the body, NR is converted to NMN before being converted to NAD+.
• NMN (nicotinamide mononucleotide) can be converted in the body to support NAD+ production. While both NR and NMN are effective options, no research currently proves one superior to the other.
• Nicotinamide and nicotinic acid are the more traditional forms of vitamin B3 that may also support NAD+ levels. However, they’ve been studied less extensively than NR or NMN.

If you’re considering NAD+ supplementation and aren't sure where to start, connecting with a licensed healthcare provider can help you identify the right approach for your health history and goals. Eden makes that process straightforward; complete a quick online intake, consult with a licensed provider, and get a personalized plan built around your needs, with ongoing provider support along the way.

‍

Final Thoughts

NAD+ is one of those molecules that quietly does an enormous amount of heavy lifting inside your body. From powering your cells’ energy production to coordinating DNA repair and activating cellular regulation proteins, it touches many aspects of overall health.

When it comes to supplementation, however, individual responses vary, and it’s always a good idea to speak with a licensed healthcare provider before adding a new supplement to your routine.