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Niacin Uses, Benefits & Risks: A Complete Look

by | Nov 24, 2020 | Last updated Feb 15, 2022

niacin vitamin b3

Casimir Funk, a Polish-born biochemist, has been credited as the first person to isolate niacin, or vitamin B3, from organic rice in the early twentieth century. There are many health benefits associated with regular use of niacin. However, the vitamin does have risks associated with it, potentially harming those who take niacin above the daily recommended intake.

Throughout its relatively short history, there has been much talk about what does niacin do, and the uses of the supplement. We’ll go into detail about niacin benefits, what it does to the body, niacin side effects, foods high in niacin, and how much niacin per day should be taken. If you decide to take niacin, it is crucial to find objective information about the compound so that you (and your healthcare provider) can determine if it is a healthy choice for you.

What is Niacin?

Niacin is sometimes called nicotinic acid and was first discovered by mixing nicotine with nitric acid. In 1873, this was first performed by the father of all niacin sources, Hugo Weidel, although it was still not known as a supplement.

He was an Austrian-born chemist who founded the compound, even though it was in writing, and was not intended to be used for further tests.

After Casimir Funk extracted the chemical decades later, it still was not known for its name today and was grouped under other a list of other chemicals called “vitamen.”

Nicotinic acid is cheap compared to other drugs and is easily accessible to obtain without a prescription. 

Nicotinamide, another form of the vitamin niacin, is a water-soluble form of niacin made by the body from poultry, fish, legumes, cereal grains, and eggs. This form of vitamin B3 is also available in supplement form. 

Foods rich in niacin are part of the Noom meal plan. Noom teaches you how to choose the healthiest foods in just the right portion sizes to control appetite and lose weight for the last time. 

Early Discovered Niacin Benefits

What is niacin used for throughout the world?

In the 1930s, niacin was taken from a human liver by Conrad Elvehjem to study Pellagra, a disease caused by niacin deficiency that damages the skin. Somewhat familiar in the developing world, it is caused by a vitamin-poor diet.

Soon after, chemists found that the vitamin could completely cure those who were suffering from Pellagra. Niacin uses, along with increased Pellagra awareness, helped to decrease the rate of Pellagra illnesses in the United States, which was common among sharecroppers and farmers, to the point of eradication. 

What is Niacin’s Function?

Once niacin reaches body tissues, it is converted to NAD or nicotinamide adenine dinucleotide. “More than 400 enzymes require NAD to catalyze reactions in the body, which is more than for any other vitamin-derived coenzyme.” 

In particular, “NAD is primarily involved in catabolic reactions that transfer the potential energy in carbohydrates, fats, and proteins to adenosine triphosphate (ATP), the cell’s primary energy currency.” 

There are various forms of NAD, including NAD+, NADH, NADP+, and NADPH. 


NAD, or nicotinamide adenine dinucleotide, is a coenzyme. You will find this coenzyme in every human cell. The two main functions of NAD are in metabolism, where it helps turn nutrients to energy, and as a helper molecule that helps proteins in the regulation of specific cellular processes. The appropriate term for NAD is NAD+. Using the generic term NAD encompasses NADH. So, NAD+ and NADH together are called NAD. 

NAD also plays a critical role in liver health. The human liver can regenerate and heal itself, but when that happens, NAD levels drop. Research shows that administering the NAD precursor nicotinamide riboside completely reversed the limitation. According to the journal Nutrients, “Nicotinamide riboside (NR) has recently become one of the most studied nicotinamide adenine dinucleotide (NAD+) precursors, due to its numerous potential health benefits mediated via elevated NAD+ content in the body.”

NAD+ levels naturally fall with age. Though human studies are still in their infancy, some mouse models show promise. “NAD+ supplementation can inhibit multiple aging features in animal models. This highlights essential roles for NAD+ in maintaining healthy aging, and suggests that NAD+ repletion may have broad benefits in humans.”

NAD+ can be converted into NADH, and when it does, it gains a charged hydrogen and two negatively-charged electrons. NADH is the most biologically active form of NAD because of the additional high-energy hydrogen. Aside from playing a part in metabolic processes, like NAD+, NADH is considered one of the most effective antioxidants. The NADH form is also commonly referred to as niacin. 

NADP+, or nicotinamide adenine dinucleotide phosphate, is a cofactor in anabolic reactions like the Calvin cycle. To work, NADP+ requires a reduced form of the phosphate called NADPH. Interestingly, even though oxidants and free radicals are touted as harmful, the NADPH system generates free radicals to fight pathogens. 

Recent research has shown that the body uses nocturnin (NOCT), a protein that “regulates metabolism under the control of circadian clock,” to convert NADP+ into NAD+ and NADPH into NADH.” This “establishes a molecular link between circadian clock and metabolism.”  This means our circadian rhythms, or at least the processes surrounding those rhythms, “directly regulates the central cofactors in anabolic and catabolic reactions.”

Did you know sleep plays a significant role in weight loss? Learn about this impact and more from daily health lessons with Noom and find out how you can lose weight for good. 

Nicotinamide Riboside – The Niacin-Like Compound

Nicotinamide riboside (NR) is a compound that is converted into NAD+ in the body. It is not niacin, but it is similar to niacin. You may also find this supplement referred to as niagen. Niagen has become the center of clinical research recently because of its unique bioavailability in humans

It is thought that NR may, indirectly through the increase in NAD+, positively affect the aging process. A specific group of enzymes activated by NAD+ is sirtuins. Sirtuins are proteins. The majority of clinical research has been completed on animals, but human research is growing. 

Sirtuins are responsible for cellular homeostasis – they keep cellular functions in balance. However, the enzymes are not activated unless in the presence of NAD+. “Since sirtuins are crucial to pathways that counter the decline in health that accompanies aging, pharmacological agents that boost sirtuin activity have clinical potential in treatment of diabetes, cardiovascular disease, dementia, osteoporosis, arthritis, and other conditions.” 

Seven sirtuins protect the body against various conditions and play various critical roles required to maintain life. SIRT1 is the most heavily researched sirtuin, but the remaining six SIRTs are gaining popularity among researchers. 

SIRT1: protects against metabolic syndrome, obesity, cardiomyopathy, reduces hypertension

SIRT2: protects against cellular hypertrophy

SIRT3: protects against dyslipidemia, plays a role in oxidative stress, lipid metabolism, reduces cellular swelling, cellular hypertrophy

SIRT4: plays a role in oxidative stress, lipid metabolism

SIRT5: plays a role in oxidative stress, lipid metabolism

SIRT6: plays a role in DNA repair, gene expression, reduces cellular hypertrophy, obesity, serum lipid levels

SIRT7: plays a role in DNA repair, gene expression

What Is Niacin Good For?

There are many essential niacin benefits for people of all ages. Niacin pills are popularly known as a supplement to treat people who are vitamin-deficient, but let’s see what other benefits may exist. 

  • Cardiovascular Health

First and foremost, “niacin has been used for primary and secondary coronary heart disease prevention for over 40 years.” That’s a long history of medical use. Research has shown up to a 6% reduction in mortality rate from the disease with niacin use. 

Things started to change as researchers began noticing that niacin may not have the assumed effect, after all. BMJ shared research in 2014 that showed niacin did not reduce mortality rates in patients with cardiovascular disease who were treated with statins. However, in studies where statin medications were not used to lower cholesterol, niacin treatment did cause a statistically significant impact on mortality rates.

Unfortunately, as the years progress, the mortality rate reduction doesn’t appear as often in clinical research. According to a 2017 study from The American Journal of Medicine, “Niacin therapy does not lead to significant reductions in total or cause-specific mortality or recurrent cardiovascular events among persons with or at risk of atherosclerotic cardiovascular disease.”

Then again, 2018 research in the journal Circulation reveals that the impact of niacin on risks involved with cardiovascular disease remain legitimate in patients who aren’t taking medications to lower cholesterol. Researchers suggest niacin may work in ways that aren’t related to cholesterol levels at all. 

The B vitamin may work by improving endothelial function, regardless of changes to cholesterol level. “Endothelial dysfunction is an independent predictor of incident atherosclerotic cardiovascular disease.”

Research in the Journal of the American Medical Association from 2019 backs up the idea that niacin effectiveness is waning. “Niacin may have some use in lipid control for secondary prevention as monotherapy, perhaps in patients intolerant to statins, but evidence is from older studies on a population potentially not representative of current-day patients.”

Overall, niacin used to be considered a contributing factor in preventing cardiovascular diseases, but recent research appears to uncover the idea that it may not be as effective as early study suggested. 

  • Cognitive Health

Niacin may be beneficial as an adjunct therapy in patients with Parkinson’s disease (PD). “Because PD patients already have low levels of niacin due to mitochondrial dysfunction, as well as the medication causing niacin depletion, higher levels were hypothesized to be more beneficial.” Niacin works as an anti-inflammatory, so researchers believe benefit comes, in part, from the potential reduction in neuroinflammation associated with PD. 

A study in Nutrition Research uncovered, “… subjects with the “low” dietary intake of protein, n-3 PUFAs, niacin, folate, and vitamin C had a significantly higher odds ratios for schizophrenia compared with those with the “high” dietary intake category of each nutrient. Therefore… sufficient dietary intake of protein, PUFAs, niacin, folate, and vitamin C is recommended for… patients with schizophrenia.”

Additional research into niacin and schizophrenia has uncovered a subset of patients who exhibit a blunted response to niacin. This could be a contributing factor to the clinical treatment of the disease. 

  • Depression

Patients currently being treated with antidepressants may benefit from niacin supplementation, according to research. Researchers believe that patients can develop niacin deficiency due to poor dietary intake and antidepressant use. The anti-inflammatory effect of antidepressants may make more tryptophan available for serotonin synthesis, ideal in patients with depression. However, as the body uses that tryptophan to produce serotonin, less becomes available downstream to develop niacin, thus causing psychiatric side effects. 

  • Obesity

After foods began being fortified with B vitamins like niacin, obesity, and diabetes prevalence increased. Research suggests there may be a connection between the two. In a 2010 study published in BMC Public Health, authors noted that “B-vitamins fortification and excess niacin consumption [may play a role] in the increased prevalence of obesity and diabetes.” 

  • Cholesterol

Extended-release niacin (ERN) is thought to help mediate the removal of cholesterol from the body via feces elimination. 

Current Medicinal Chemistry shares, “Studies have since shown that niacin may decrease fasting levels of plasma very low- density lipoproteins (VLDL), low-density lipoprotein cholesterol (LDL-C), and lipoprotein [a] (Lp[a]), while may increase high-density lipoprotein cholesterol (HDL-C).”

The increase in HDL, or healthy cholesterol, associated with niacin has been challenged in recent years. Despite decades of use for many aspects of cardiovascular health, including cholesterol maintenance, antibodies may negate any positive effects of niacin. “The rise in HDL‐C achieved with ERN was not matched by improved antioxidant capacity, eventually hampered by the emergence of aApoA‐I antibodies. These results may explain why Niacin and other lipid-lowering agents fail to reduce cardiovascular risk.”

  • Blood Pressure

Niacin exerts an additive reaction with blood pressure medications,” which means frequent blood pressure readings should be taken when taking niacin with these prescription drugs. Specific interactions have been noted for “amlodipine clozapine, bisoprolol, and diltiazem.”

As for blood-pressure-lowering abilities, in healthy college-aged men, it appears that niacin may lower blood pressure. Still, future research is needed to determine if this function has a place in athletics. According to the International Journal of Exercise Science, “Based on the results of this investigation we have demonstrated that acute niacin supplementation of 1000mg significantly decreased resting systolic and diastolic blood pressure, and resting heart rate post-consumption. Follow up experiments are focused on the effects of niacin supplementation on pre-exercise, exercise, and post-exercise blood pressure and heart rate, in a cross-over fashion, in college-aged recreational athletes.”

  • Diabetes

The effect of niacin on the potential for developing diabetes has left researchers with exciting results. According to a review of nearly 40 years of study, researchers have found that “Niacin therapy is associated with a moderately increased risk of developing diabetes regardless of background statin or combination laropiprant therapy.” That’s an increased risk, not decreased risk. 

There is some early evidence that niacin, in patients with type 2 diabetes mellitus (T2DM), helps “improve lipid abnormalities.”

Jump forward to 2020, and some of the newest research supports this idea. “Niacin supplementation could improve lipid profiles without affecting the glycemic levels for patients with T2DM,” according to the journal Medicine.

  • Cancer

We found mixed results when researching the effect of niacin on skin cancer. According to the International Journal of Cancer, niacin may help reduce the risk of squamous cell carcinoma but may increase the risk of basal cell carcinoma – thus negating any positive effect.

However, a 12-month study of the effect of oral nicotinamide on the rate of new skin cancer development showed the B vitamin decreased new nonmelanoma cases by nearly 25%. This study was part of the phase 3 human trial published in the New England Journal of Medicine.

Now, in smokers, there may be a decent benefit to niacin intake. Research showed that when the body is deficient in niacin, it cannot effectively perform the DNA damage repair process. “…niacin‐deficient population are at the higher risk of genetic instability caused by cigarette smoke carcinogen NNK.”

There’s also research that shows nicotinic acid may play a role in the prevention of pancreatic cancer, though researchers note additional studies are needed to verify the connection. 

In patients with cancer who’re undergoing chemotherapy, niacin plays a significant role in fighting the side effects of treatment. “… niacin can decrease the side effects of cancer treatment from different directions, including side effects, nausea, vomiting, loss of sense of taste.”

  • Neuromuscular Disease

Mitochondrial myopathies are a group of neuromuscular diseases caused by damage to the mitochondria—small, energy-producing structures that serve as the cells’ “power plants.” Nerve cells in the brain and muscles require a great deal of energy, and thus appear to be particularly damaged when mitochondrial dysfunction occurs.” Research has shown that “pathogenesis of mitochondrial myopathy in humans that can be targeted by the administration of the NAD+ precursor niacin, identifying NAD+ boosting as a potential treatment for this devastating disease.”

Another study delivered increasing doses of NAD+-booster niacin to patients with mitochondrial myopathy. “Blood NAD+ increased in all subjects, up to 8-fold, and muscle NAD+ of patients reached the level of their controls. Some patients showed anemia tendency, while muscle strength and mitochondrial biogenesis increased in all subjects. In patients, muscle metabolome shifted toward controls, and liver fat decreased even 50%.”

  • Arthritis

In the late 1990s, niacin appeared on the radar of researchers hoping to find a treatment for osteoarthritis. After 12 weeks of supplementation, the authors concluded that “niacinamide may have a role in the treatment of osteoarthritis. Niacinamide improved the global impact of osteoarthritis, improved joint flexibility, reduced inflammation, and allowed for reduction in standard anti-inflammatory medications when compared to placebo.”

  • Premature Ovarian Failure

Though research is preliminary and human studies have yet to confirm mouse models, it appears that niacin may impact ovarian development, essentially increasing the number of developing follicles. This could positively impact fertility in women. 

  • Bone Health

Getting just the right amount of niacin may be more important than we think, especially in terms of aging and bone health. Researchers have found that niacin levels that are too low or too high increase the likelihood of hip fractures in aging men and women.

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How Much Niacin Is Safe?

The amount of niacin a person needs depends on gender and age. Recommended amounts of niacin intake are often measured as NE or niacin equivalents. This is because the body produces some niacin from the amino acid tryptophan. Thus, the total suggested intake is measured in equivalents. 

  • “Infants 7-12 months: 4mg NE
  • Children 1-3 years: 6mg NE
  • Children 4-8 years: 8mg NE
  • Teen boys 14-18 years: 16mg NE
  • Teen girls 14-18 years: 14mg NE
  • Adult men 19+ years: 16mg NE
  • Adult women 19+ years: 14mg NE
  • Pregnant teens and women: 18mg NE
  • Breastfeeding teens and women: 17mg NE”

There are also upper limits established by the National Institutes of Health. These are the limits to how much niacin should be taken in the form of dietary supplements. 

  • “Children 1-3 years: 10mg
  • Children 4-8 years: 15mg
  • Children 9-13 years: 20mg
  • Teens 14-18 years: 30mg
  • Adults 19+ years: 35mg”

Excessive intake of niacin can cause side effects, so keeping within these limits is essential. 

Niacin Side Effects – Why Does Niacin Cause Flushing?

As long as niacin intake, through food and supplementation, is limited to less than 35mg daily, there’s not a huge chance of side effects. However, in larger quantities, side effects can occur. 

Mild side effects include:

  • Intestinal gas
  • Stomach discomfort or upset
  • Dizziness
  • Mouth pain

According to MedlinePlus.gov, “When doses over 3 grams [3000 mg] per day of niacin are taken, more serious side effects can happen. These include liver problems, gout, ulcers of the digestive tract, loss of vision, high blood sugar, irregular heartbeat, and other serious problems.”

What about niacin flushing?

Niacin dilates skin capillaries, allowing more blood flow just under the surface of the skin. The effect is felt by nearly everyone taking larger niacin doses, either by prescription means or over the counter. Flushing has been compared to an allergic reaction, making it difficult to differentiate between regular niacin flushing and a response that requires medical attention. 

Research has shown that taking aspirin with niacin can reduce flushing by up to 50%. If you are taking prescription medications of any kind, especially blood thinners, seek advice from your healthcare provider before taking aspirin as it’s proven to thin blood.

Niacin flushing is generally considered harmless and should subside within one to two hours of taking the vitamin. 

Niacin Deficiency

Pellagra, briefly mentioned before, is a result of niacin deficiency. Thanks to the fortification of many foods with the B vitamin, pellagra is a condition that’s rarely seen in developed countries today. 

“Initially, neurological changes such as anxiety, poor concentration, fatigue, and depression can manifest, but as pellagra advances, dementia, and delirium may occur. Also, gastrointestinal complications, glossitis, cheilosis, stomatitis, nausea, vomiting, and diarrhea or constipation may be present,” according to the National Institutes of Health

Because the human body can convert tryptophan into niacin, there must also be a tryptophan deficiency for pellagra to develop. Because of the rarity of the condition and the circumstances that must occur for pellagra to develop, most affected are also deficient in vitamin B6, protein, and riboflavin. 

Niacin deficiency can also occur in cases of alcoholism, diarrhea, cirrhosis, “nervous anorexia, AIDS, cancer, and chemotherapy, as well as malabsorptive disorders, such as Crohn’s disease.” 

Foods High In Niacin

Most diets naturally provide for all the niacin the body needs either directly or indirectly, as the body can produce niacin from the amino acid tryptophan found in proteins. 

Foods high in niacin include:

Meat and Seafood (per 2.5-ounce serving)

  • Tuna: up to 20mg
  • Salmon: up to 17mg
  • Liver: up to 17mg
  • Chicken: up to 15mg
  • Pork, beef, lamb: up to 14mg
  • Mackerel: up to 12mg
  • Rainbow trout: up to 10mg
  • Turkey: up to 9mg
  • Cooked bacon: up to 8mg

Fruits and Vegetables

  • Portobello mushroom: 8mg per cup, sliced
  • White mushrooms: 7mg per cup, cooked
  • White potato: 4mg per large, baked
  • Green peas: 3mg per cup, cooked
  • Red potato: 3mg per medium, baked
  • Yellow corn: 3mg per cup
  • Sweet potato: 2mg per cup,  mashed
  • Asparagus: 2mg per cup, canned
  • Yellow pepper: 2mg per large
  • Serrano pepper: 2mg per cup, chopped

Nuts and Seeds

  • Peanuts: 4mg per ounce, dry-roasted
  • Hemp seeds: 3mg per ounce
  • Chia seeds: 3mg per ounce
  • Sunflower seeds: 2mg per ounce
  • Coconut milk: 1mg per cup

All foods high in niacin are allowed on the Noom program. That’s because all foods are permitted on Noom. Noom doesn’t prohibit foods, eliminate food groups, or restrict the user in any way. You can lose weight eating the foods you love and keep it off for good. 

Who Should Take a Niacin Supplement?

Are niacin supplements necessary for anyone? Or, do we get enough in our diets to cover all the body’s needs? According to the National Institutes of Health, most developed countries get more niacin than they need daily. Estimates show an average intake of about 20mg daily in children, adolescents, and women, and 30mg daily in men. It is thought that about 1% of adults are at risk of niacin deficiency. 

However, this hasn’t stopped people from taking niacin supplements. About 20% of people aged two and older take a supplement that contains niacin. When age is taken into account, the percentage of adults using niacin-containing supplements skyrockets to around 40% for ages 60 and older. Of these people, about 10% are taking niacin supplements that supply more than the daily recommended intake.

So, who should be taking niacin supplements? All niacin supplementation should be covered with your healthcare provider before starting because there are potential side effects of taking too much niacin. However, undernourished people living with alcoholism, carcinoid syndrome, or Hartnup disease may need additional supplementation.  

What Did We Learn About Niacin?

Niacin plays a critical role in metabolism and a long list of enzymatic reactions. Without niacin, the body would be unable to convert the food we eat to energy. Though the suggested upper limit for niacin is 35mg daily, the medical community has been using high-dose niacin to treat a variety of health conditions for more than 40 years. 

The best way to get all the niacin you need is through a healthy, well-balanced diet. Noom can help you learn how to eat better, so you get all the nutrients you need and lose weight in the process. Check it out today!

Questions and Answers on Niacin

Is niacin good for you?

Niacin is a vitamin that’s necessary for more than 400 body functions. Without adequate levels of the B vitamin, pellagra will develop, and life-threatening side effects could occur. 

Why does niacin make you flush?

Niacin dilates the capillaries near the surface of the skin, so more blood flows through. This dilation causes a warming, sometimes burning sensation that can last up to two hours. 

Is it safe to take 500mg of niacin a day?

The suggested upper limit for niacin intake is 35mg daily. High-dose niacin may be prescribed by a healthcare provider but should not be attempted without proper advice from a professional.

What is the most common side effect of niacin?

The most common side effect of niacin is skin flushing. 

Why do people take niacin?

Niacin has been used for decades to improve heart health, lower bad cholesterol, increase healthy cholesterol, regulate blood pressure, and improve cognitive health. 

Does niacin remove plaque from arteries?

Niacin doesn’t directly remove plaque from arteries, but it does help raise healthy cholesterol (HDL) that can help remove plaque from arterial walls. 

Does niacin give you energy?

Niacin is necessary to break down proteins, fats, and carbohydrates into energy that the body can use. 

When should you take niacin?

Niacin is often administered at bedtime. 

Is niacin good for anxiety?

There’s been some debate about whether or not niacin helps anxiety. Most of the focus is on niacinamide, which is an amide of niacin. 

Does niacin raise blood pressure?

Niacin, based on some clinical research, may lower blood pressure, not raise blood pressure.