Oxidized nicotinamide adenine dinucleotide (NAD+) is crucial to over 500 enzyme reactions in your body. NAD+ can be derived from tryptophan.
Levels of NAD+ are reduced with aging and conditions like the following:
This article covers the latest evidence for using NAD+ supplements and some safety concerns to be aware of if you decide to use them.
What Is NAD+?
NAD+ is a coenzyme that is important for many pathways in the body, including the following:
- Cellular energy
- DNA repair
- Hormone signaling
It also helps maintain metabolism and circadian rhythm (the 24-hour internal clock regulating sleep cycles).
Significantly, signaling proteins called sirtuins require NAD+ to regulate age-related changes and extend life span.
Mehmel M, Jovanović N, Spitz U. Nicotinamide riboside-The current state of research and therapeutic uses.
Is NAD+ the Same as NADH?
Nicotinamide adenine dinucleotide, or NAD, can come in two forms, as follows:
- NADH, “reduced” NAD, meaning it has an extra electron
- NAD+, “oxidized” NAD, meaning it lost an electron
NADH is different from NAD+.
Do Foods Contain NAD+?
Several precursors(a substance that can form other substances) can increase NAD+ levels in the body. You can get these precursors through supplements or foods. Precursors that increase NAD+ levels include the following:
- Nicotinic acid (also known as niacin or vitamin B3)
- Niacinamide (another form of vitamin B3)
- Nicotinamide mononucleotide (NMN), the FDA has considered NMN to be investigational drug and not a supplement
- Nicotinamide riboside (NR)
Good food sources of tryptophan and niacin include the following:
You can also find some niacin in the following vegetarian foods:
- Dairy products
- Enriched grains
- Soy products
- Whole grains
Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist (RD or RDN), pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.
Because levels of NAD+ decrease with aging, it’s theorized that supplements that boost NAD+ could slow the effects of aging and extend life span.
NAD+ and its precursors have been studied in preclinical trials (using cells in test tubes or animal models) for the following conditions:
- Alzheimer’s disease
- Amyotrophic lateral sclerosis (ALS)
- Huntington’s disease (HD)
- Parkinson’s disease (PD)
- Vascular dementia
- Cognitive decline
- Heart protection
- Traumatic brain injury
- Ocular (eye) degeneration
- Metabolic dysfunction-associated steatotic liver disease (MASLD, formerly known as nonalcoholic fatty liver disease or NAFLD)
Results seen in animal or lab studies may or may not be replicated in humans. NAD+ is not currently recommended for any of these conditions.
NAD, NMN, and NR have been studied in human clinical trials for the following conditions:
Many of these trials were very small and included 30 or fewer people. Large-scale studies are needed before these supplements can be recommended.
Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.
There aren’t many studies on the effects of NAD+ supplements in humans. So, it is unknown how to dose these supplements. Dosage will depend on your product and what you use it for.
NAD+ can be increased by tryptophan, NMN, NR, and niacin or niacinamide food sources or supplements.
And keep in mind that optimal dosing or duration of NAD+ supplements have not been established yet.
Clinical trials have used the following doses:
- 250 milligrams (mg) of NMN daily for metabolic benefits in females with prediabetes
- 1,000 mg of NR daily to improve body composition in people with obesity
- 1,000 mg of NR daily for Parkinson’s disease
Dietary supplements are not regulated the same way as drugs in the United States, meaning the Food and Drug Administration (FDA) does not approve them for safety and effectiveness before products are marketed. Choose a supplement tested by a trusted third party, such as the U.S. Pharmacopeia (USP), ConsumerLab.com, or NSF.org, whenever possible.
However, even if supplements are third-party tested, they are not necessarily safe for all or effective in general. Therefore, talking to your healthcare provider about any supplements you plan to take and checking in about potential interactions with other supplements or medications is important
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