Everything below concerns nicotinamide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-07-09. Numbers and descriptions here follow the published literature rather than marketing material.
NAD+ is a dinucleotide composed of nicotinamide, ribose, and adenine linked by phosphate groups. Its full name is nicotinamide adenine dinucleotide, with "+" denoting the oxidized form. The molecule acts as a coenzyme in redox reactions, cycling between NAD+ and NADH. In cells, it participates in electron transfer during glycolysis, the citric acid cycle, and oxidative phosphorylation. It is distinct from NADP+, which carries an additional phosphate group and supports different biosynthetic reactions.
Beyond redox chemistry, NAD+ serves as a substrate for enzymes that transfer ADP-ribose or remove acetyl groups. Sirtuins, PARPs, and CD38-family enzymes consume NAD+ and produce nicotinamide and ADP-ribose-related products. These reactions link NAD+ availability to DNA repair, chromatin modification, and cellular signaling. Because the molecule is central to energy metabolism and regulation, changes in its concentration are studied in aging, immunity, and metabolic research. The balance between synthesis and consumption varies by tissue, developmental stage, and physiological state.
In humans, NAD+ can be synthesized from nicotinic acid, nicotinamide, nicotinamide riboside, and tryptophan through overlapping pathways. The salvage pathway recycles nicotinamide back to NAD+ and is often considered a major route in many tissues. Dietary precursors and intracellular recycling both contribute to the pool, but the quantitative importance of each source remains an active research question. NAD+ levels are not uniform across organs or cell compartments. Measurements in blood do not necessarily reflect concentrations inside tissues.
Beyond redox chemistry, NAD+ is consumed as a substrate by enzymes that transfer ADP-ribose or remove acetyl groups. Sirtuins use NAD+ in deacylation reactions, poly(ADP-ribose) polymerases use it in DNA damage responses, and CD38 hydrolases convert it to signaling metabolites. Because these enzymes compete for the same pool, changes in NAD+ availability can influence multiple cellular processes. The relative contribution of each consumption route differs by cell type and condition, and precise quantitative links remain an active area of study.
Research on NAD+ spans biochemistry, aging biology, and metabolism. Studies often examine how NAD+ levels change with age, diet, exercise, or disease states, and whether precursor supplementation alters those levels. Findings in animal models do not automatically translate to humans, and measurement methods vary across studies. Questions about tissue-specific effects, long-term consequences, and causal relationships remain open. NAD+ itself is not established as a single therapeutic agent with a broad clinical role.
Nicotinamide adenine dinucleotide, abbreviated NAD+, is a dinucleotide composed of two nucleotides joined by phosphate groups. One nucleotide contains adenine; the other contains nicotinamide. The molecule exists in oxidized (NAD+) and reduced (NADH) forms, and the reversible hydride transfer between them underlies many metabolic oxidation-reduction reactions. In cells, NAD+ serves as an electron acceptor in pathways such as glycolysis, the citric acid cycle, and oxidative phosphorylation. Its concentration and redox ratio vary by compartment, tissue, and metabolic state.
| Property | Value | Notes |
|---|---|---|
| Common name | Nicotinamide adenine dinucleotide (oxidized) | Often shortened to NAD+ |
| Chemical class | Dinucleotide | Contains nicotinamide and adenine moieties |
| Molecular formula | C21H27N7O14P2 | Free acid form; charge depends on pH |
| Molar mass | About 663.43 g/mol | Calculated for C21H27N7O14P2 |
| CAS number | 53-84-9 | Common identifier for beta-NAD+ |
Laboratory handling of NAD+ follows standard practices for hygroscopic fine chemicals. Personnel typically avoid inhalation and skin contact, use gloves and eye protection, and work in a ventilated area. Quality control may include ultraviolet absorbance at the nicotinamide maximum, chromatographic purity, water content, and identity confirmation by mass spectrometry. Because commercial preparations can contain counterions, residual solvents, or related nucleotides, a certificate of analysis helps verify the material. Researchers should confirm that the form supplied matches the intended assay.
Measuring NAD+ in biological samples requires care because the molecule is chemically reactive and present at low concentrations in some tissues. Common approaches include enzymatic cycling assays, high-performance liquid chromatography, and liquid chromatography coupled to mass spectrometry. Each method has different sensitivity and specificity, and sample preparation can affect results. Acidic or alkaline extraction steps are used in some protocols, but the choice depends on the analyte and matrix. No single method is universally optimal for every tissue or fluid.
Solid NAD+ is relatively stable when kept dry, cold, and protected from light. Aqueous solutions are more vulnerable to hydrolysis and can lose activity during repeated freeze-thaw cycles or prolonged storage at ambient temperature. Stability depends on pH, ionic strength, and the presence of degrading enzymes or metal ions. For many laboratory uses, aliquots are stored frozen and thawed only once. Exact degradation rates vary by matrix, so stability should be checked for each application rather than assumed.
Cells produce NAD+ through several biosynthetic routes. The salvage pathway recycles nicotinamide, while the Preiss-Handler pathway uses nicotinic acid, and a de novo route can start from tryptophan in some organisms. In mammals, the salvage pathway is generally considered the main source under ordinary conditions. Tissue concentrations vary widely by cell type and compartment, and measured declines with age have been reported in some studies. Whether such changes drive aging or mainly accompany it remains an open question.
Nicotinamide adenine dinucleotide, commonly abbreviated NAD+, is a coenzyme present in all living cells. The molecule consists of two nucleotides linked by phosphate groups, with adenine and a nicotinamide ring as its principal features. In its oxidized form, the nicotinamide ring can accept a hydride ion, becoming NADH. This reversible conversion places NAD+ at the center of many electron-transfer reactions. Its role as a redox carrier is well established across bacteria, plants, fungi, and animals.
CYP2D6 inhibitors (e.g., fluoxetine, paroxetine and quinidine) can increase exposure for atomoxetine and it can also increase atomoxetine steady-state plasma concentration. Antihypertensive drugs because it can possibly increase the blood pressure β2-agonist e.g. albuterol because it may increase the efficacy of albuterol on the cardiovascular system. Medicines that affect norepinephrine (e.g. venlafaxine, imipramine, mirtazapine) should be used with caution when administered with atomoxetine due to possible synergy or synergistic effects on pharmacodynamic effects. Beware of taking reboxetine in combination with:
==== White Americans ==== As of 2018, 41.3% of white American men over the age of 20 are obese, while 39% of white women in this age cohort are obese. However, newer data from 2025 suggests that the actual obesity rate for White Americans is around 65%, based on anthropometric measurements alone rather than BMI. This newer study did not segregate Hispanics as a race and includes people identifying as both "White" and "Hispanic".
=== Liquid chromatography-liquid chromatography === Two-dimensional liquid chromatography (2D-LC) combines two separate analyses of liquid chromatography into one data analysis. Modern 2D liquid chromatography has its origins in the late 1970s to early 1980s. During this time, the hypothesized principles of 2D-LC were being proven via experiments conducted along with supplementary conceptual and theoretical work. It was shown that 2D-LC could offer quite a bit more resolving power compared to the conventional techniques of one-dimensional liquid chromatography. In the 1990s, the technique of 2D-LC played an important role in the separation of extremely complex substances and materials found in the proteomics and polymer fields of study. Unfortunately, the technique had been shown to have a significant disadvantage when it came to analysis time. Early work with 2D-LC was limited to small portion of liquid phase separations due to the long analysis time of the machinery. Modern 2D-LC techniques tackled that disadvantage head on, and have significantly reduced what was once a damaging feature. Modern 2D-LC has an instrumental capacity for high resolution separations to be completed in an hour or less. Due to the growing need for instrumentation to perform analysis on substances of growing complexity with better detection limits, the development of 2D-LC pushes forward. Instrumental parts have become a mainstream industry focus and are much easier to attain then before.
== Glycoside hydrolases == Glycoside hydrolases (or glycosidases), are enzymes that break glycosidic bonds. Glycoside hydrolases typically can act either on α- or on β-glycosidic bonds, but not on both. This specificity allows researchers to obtain glycosides in high epimeric excess, one example being Wen-Ya Lu's conversion of D-Glucose to Ethyl β-D-glucopyranoside using naturally-derived glucosidase. Wen-Ya Lu utilized glucosidase in a reverse manner opposite to the enzyme's biological functionality:
Sources: en.wikipedia.org
Studies of twin adults indicate a 0.36 to 0.48 genetic influence on the likelihood of developing migraine. However, few studies examine non-European populations or distinguish between migraine with aura and migraine without aura. It is clear from family and population studies that migraine is a complex disorder, where numerous genetic risk variants exist, and where each variant increases the risk of migraine marginally. It is also known that having several of these risk variants increases the risk by a small to moderate amount. Single gene disorders that result in migraine are rare. One of these is known as familial hemiplegic migraine, a type of migraine with aura, which is inherited in an autosomal dominant fashion. Three main genes are involved in familial hemiplegic migraine via ion transport: CACNA1A, ATP1A2, and SCN1A. Another genetic disorder that has been associated with migraine is CADASIL syndrome (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy). Despite some similarities in symptoms, ICHD-3 recommends using the diagnosis "headache attributed to CADASIL" (code 6.8.1) rather than migraine with aura (MA) or migraine without aura (MO) (codes 1.1 and 1.2). The TRPM8 gene, which codes for a cation channel, has been linked to migraine. One meta-analysis found a protective effect from angiotensin converting enzyme polymorphisms on migraine. The common forms of migraine are polygenetic, where common variants of numerous genes contribute to the predisposition for migraine.
=== Differentiation === CAFs can also be derived from differentiation of other cell types such as mesenchymal stem cells, which was proved in murine models with cancers such as glioma, breast, pancreatic and gastric cancers. Another suggested origin is differentiation of endothelial or epithelial cells via trans-differentiation or epithelial to mesenchymal transition, respectively. Less common origin of CAFs is by differentiation of other tumor adjacent cells such as epithelial or endothelial cells, adipocytes, pericytes and smooth muscle cells. Adipocytes, especially white adipocytes transdifferentiate into CAFs upon activation with TGF-β1. Through TGF-β1 can be transformed also peritoneal mesothelial cells. It has been suggested that CAFs are better conceptualised as a “cell state” Research has found that CAF trans-differentiation can be caused by epigenetic factors.
The legislative bill is aimed at strengthening capabilities in the area of technology, such as quantum computing and AI specifically to face the competitive threat from China perceived as urgent. Senator Chuck Schumer, the leader of the Senate majority and one of the sponsors of the industrial policy bill invoked the threat of authoritarian regimes that want “grab the mantle of global economic leadership and own the innovations”. In 2022, U.S. Innovation and Competition Act was amended and turned into the Chips and Science Act with planned spending of 280 billion US dollars, 53 billion thereof are allocated directly to subsidies for semiconductors manufacturing. Commentators identified possible positive effects on innovation from the US attempts to compete with China in a perceived rivalry. Among the main beneficiaries of the US CHIPS Act are the semiconductor producers Intel, TSMC and Micron Technology.
=== Buddhism and coffee consumption === Another group of Koreans who have increased their consumption of coffee are Korean Buddhist. In Korea today some major monasteries say that over half of the meditation monks have switched to coffee. Making coffee and sharing it with visitors is also rationalized as a way for Buddhism to remain relevant in contemporary society. The type of coffee normally associated with the Korean monastic community is hand-drip coffee. That is because monks may want to be associated with Korean high-culture which is associated with hand-drip coffee. Additionally, there are many tools and steps involved with hand-drip coffee which mirror the ceremony of making tea. As an example of how the Korean Buddhist community has embraced coffee one can turn to the Puramsa, Torisa, and other monastic grounds where cafes were established.
=== Bolus timing === Since the pump user is responsible to manually start a bolus, this provides an opportunity for the user to pre-bolus to improve upon the insulin pump's capability to prevent postprandial hyperglycemia. A pre-bolus is simply a bolus of insulin given before it is actually needed to cover carbohydrates eaten. There are two situations where a pre-bolus is helpful:
Sources: en.wikipedia.org
Physical presence may be required for women who are in relationships for the testosterone–partner interaction, where same-city partnered women have lower testosterone levels than long-distance partnered women.
=== Trump administration claims === The Trump administration alleges the vessels destroyed were operated by narcoterrorists or members of cartels or gangs. The Guardian stated on 6 November 2025 that "governments and families of those killed in the US strikes on alleged drug boats have said many of the dead were civilians—primarily fishers." Sean Parnell stated that Department of Defense intelligence "consistently ... confirm[ed] that the individuals involved in these drug operations were narco-terrorists, and we stand by that assessment". Names and surnames of people missing and suspected killed in the strikes have rarely been made public and information has been repressed by the Venezuelan government, or families have avoided speaking out of fear. Dozens of those killed have not been identified; as of 8 November, those identified publicly include two Colombians, one Ecuadorian, two men from Trinidad and Tobago, and nine Venezuelans. The family of a Colombian fisherman presumably killed in the 15 September strike stated that Alejandro Andrés Carranza Medina, alias 'Coroncoro', was not trafficking drugs, but according to CBS News, "... media have reported that Carranza had a criminal record for stealing weapons in collusion with gangs". Colombia's El Tiempo reported that in 2015 he was "allegedly involved in the theft of 264 weapons from the Santa Marta Metropolitan Police"; El País stated that the alleged perpetrator "accepted the charges of conspiracy to commit a crime, embezzlement, falsification of public documents and aggravated theft".
== Genomics == The genome of B. cereus has been characterized and shown to contain over 5 million bp of DNA. Out of these, more than 5500 protein-encoding genes have been identified, of which the top categories of genes with known functions include: metabolic processes, processing of proteins, virulence factors, response to stress, and defense mechanisms. Many of the genes categorized as virulence factors, stress responses, and defense mechanisms encode factors in antibiotic resistance. There are approximately 600 genes which are common in 99% of the taxa of B. cereus sensu lato, which constitutes around 1% of all genes in the pan-genome. Due to the prevalence of horizontal gene transfer among bacteria, the pan-genome of B. cereus is continually expanding. The GC content of its DNA across all strains is approximately 35%. Following exposure to non-lethal acid shock at pH 5.4–5.5, the arginine deiminase gene in B. cereus, arcA, shows substantial up-regulation. This gene is part of the arcABC operon which is induced by low-pH environments in Listeria monocytogenes, and is associated with growth and survival in acidic environments. This suggests that this gene is also important for survival of B. cereus in acidic environments. The activation of virulence factors has been shown to be transcriptionally regulated via quorum-sensing in B. cereus. The activation of many virulence factors secreted is dependent on the activity of the Phospholipase C regulator (PlcR), a transcriptional regulator which is most active at the beginning of the stationary phase of growth.
Collins went on to speak about her life and career, discussing her early jobs and how they helped with independence, as well as her love of reading books by Enid Blyton as a child. She also spoke about the changes and how times had moved on since she was at school, endorsing a ban on mobile phones for under-16's, as well as encouraging children to "get a craft behind them and a skill set" and to follow a career path they were passionate about. Collins also suggested that they be taught life and money management skills, before concluding by stating that if she was Secretary of State for Education, she'd deliver a morning motivational message via the television. Collins was not paid for the campaign. The Department for Education received criticism for using Collins in the social media campaign, with some suggesting that the videos "trivialised issues in care for children with Special educational needs (SEN)". Phillipson defended Collins however, stating that some of the criticism had been "outright snobbery and just downright unpleasant", arguing that Collins had a reach "politicians [couldn't] reach". Collins subsequently visited Focus 1st Academy in London, a school specialising in pupils with SEN, with whom she met and delivered a speech to. The school's headteacher Marina Savva described Collins as "one of the most uplifting inspirational speakers we've ever had".
=== Animal rights === Barker was a vegetarian. In 1982, Barker began ending The Price Is Right episodes with the phrase: "This is Bob Barker reminding you to help control the pet population – have your pets spayed or neutered." Though Barker had already been dabbling in animal rights before meeting Burnet, his efforts became more aggressive during his relationship with her. In 1987, Barker requested the removal of fur prizes for the Miss USA pageant and stepped down as host when the producers refused. In 1989, Barker and United Activists for Animal Rights publicly accused several media projects and the American Humane Association of animal mistreatment and condoning animal mistreatment, a tactic which resulted in a $10 million suit against him and the UAAR for libel, slander, and invasion of privacy. The suit was finally settled by the insurer in 1994. Barker founded DJ&T Foundation in 1994, named after his late wife and mother, which has contributed millions of dollars to animal-neutering programs and funded animal rescue and park facilities all over the United States. In 2004, Barker donated $1 million (equivalent to $1.7 million in 2025) to Columbia Law School to support the study of animal rights. In 2009, Barker wrote a letter about three businesses in Cherokee, North Carolina, asking them to close their bear exhibits. He threatened to not attend the 2009 Game Show Awards, where Barker was to receive a lifetime achievement award, because Betty White would be attending.
Sources: en.wikipedia.org
The plus sign indicates the oxidized form of nicotinamide adenine dinucleotide, which can accept electrons. When it accepts electrons, it becomes NADH. The two forms together support redox reactions in cells.
No. NAD+ is the oxidized form and NADH is the reduced form. They differ by two electrons and a proton equivalent, and cells interconvert them during metabolism.
Yes. NAD+ is present in all living cells and is required for fundamental metabolic reactions. Its concentration varies by tissue, compartment, and time.
NAD+ is a coenzyme found in all living cells. It carries electrons in metabolic reactions and also serves as a substrate for enzymes involved in signaling and DNA repair. Its oxidized and reduced forms are central to energy metabolism.