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How vitamin B3 could be the secret to a long life and protecting your heart
Last reviewed: 02.07.2025

Learn how an important nutrient in your diet may hold the secret to longer life and heart health, thanks to groundbreaking discoveries about the role of niacin in metabolic and cellular rejuvenation.
A study published in the journal Scientific Reports shows that dietary vitamin B3 intake may reduce the risk of total and cardiovascular mortality in adults.
Vitamin B3, also known as niacin, is a water-soluble micronutrient that is vital for a variety of physiological processes. Niacin deficiency can lead to serious health problems, including pellagra, a severe disease characterized by dermatitis, diarrhea, dementia, and death.
Foods rich in niacin include tuna, salmon, turkey, peanuts, and fortified packaged foods, which are a convenient source of vitamin B3 in the diet.
In some countries, wheat flour and cereals are fortified with niacin to prevent pellagra. In addition, common foods such as beef, pork, chicken, coffee, and tea contain large amounts of niacin.
Thus, niacin is a common micronutrient in modern Western diets, especially in the United States, where its intake exceeds three times the recommended daily allowance.
Niacin is widely known for its therapeutic effects on dyslipidemia. Several studies have shown that niacin can significantly reduce the levels of low-density lipoprotein (bad cholesterol) and increase the levels of high-density lipoprotein (good cholesterol) in the blood.
The results of studies on the cardioprotective effects of niacin are mixed. This phenomenon, known as the “niacin paradox,” shows instances where improving lipid profiles does not always lead to better cardiovascular outcomes. Some studies have shown modest beneficial effects of niacin on cardiovascular events, while others have found no reduction in the risk of cardiovascular events and even noted an increase in the risk of all-cause mortality.
Given the paucity of information on the effects of niacin on long-term health outcomes, the present study was conducted to examine the association between dietary niacin intake and causes of cardiovascular mortality in the general US population.
The study included 26,746 adults who participated in the National Health and Nutrition Examination Survey (NHANES) 2003–2018. The median follow-up period was 9.17 years.
Niacin intake was determined using two 24-hour dietary surveys. Participants were divided into four groups based on their average niacin intake over the two days.
Statistical analysis was performed to compare the risk of all-cause and cardiovascular mortality among participants divided into different quartiles of niacin intake. Sensitivity analyses, such as excluding participants with pre-existing cardiovascular disease (CVD) or cancer, confirmed the robustness of the results.
During the follow-up period, there were 3,551 all-cause deaths and 1,096 cardiovascular deaths.
The analysis showed a negative association between dietary niacin intake and the risk of total and cardiovascular mortality. Participants with the highest niacin intake had a lower risk of death compared with those with the lowest niacin intake.
A dose-response association was observed: as niacin intake increased, the risk of all-cause and cardiovascular mortality decreased. However, the benefits plateaued at intake levels above the median of 22.45 mg/day.
Niacin supplements, despite their benefits, can cause side effects such as skin flushing and, in excessive doses, liver toxicity or hyperglycemia, highlighting the need for their controlled use.
Subgroup analyses by age, sex, ethnicity, education level, smoking, alcohol consumption, body mass index (BMI) and health conditions showed that the effect of niacin on the risk of all-cause mortality was greater in people without diabetes than in diabetics.
With respect to the reduction in risk of cardiovascular mortality, the beneficial effect of niacin was observed in several subgroups, including older adults, women, non-Hispanic whites, people with higher levels of education, smokers, and people with obesity and without hypertension, diabetes, dyslipidemia, or cardiovascular disease. Baseline characteristics showed that people with higher niacin intake tended to be younger, more educated, and more likely to smoke or drink alcohol.
The study found an inverse association between dietary niacin intake and the risk of all-cause and cardiovascular mortality among US adults.
The potential benefits of niacin may be related to improved nicotinamide adenine dinucleotide (NAD) metabolism. As a precursor to NAD, niacin can increase NAD levels, improve cellular metabolism and mitochondrial function, and reduce DNA damage, inflammation, cell death, and aging through a variety of mechanisms.
Niacin has been shown to reduce chemotherapy-associated muscle loss in cancer patients by restoring tissue NAD levels and improving mitochondrial metabolism. Niacin also improves muscle performance in adult mitochondrial myopathy by reversing systemic NAD deficiency and increasing mitochondrial biogenesis and functionality.
These observations help to understand how niacin reduces mortality risks.
The cardiovascular benefits of niacin may be related to its role in lipid lowering. As a potent G protein-coupled receptor agonist, niacin can inhibit lipolysis and reduce free fatty acid formation.
Recent studies suggest that niacin metabolites such as 2PY and 4PY may activate inflammatory pathways that contribute to cardiovascular risk. This highlights the need for further study of niacin’s dual effects on health.
The study shows that the effect of niacin in reducing the risk of overall mortality is more pronounced in people without diabetes. In this context, previous studies have shown that niacin increases the risk of diabetes by increasing blood glucose levels and decreasing insulin sensitivity.
These observations suggest that higher niacin intake may be recommended to reduce the risk of all-cause mortality in people without diabetes, but not in patients with diabetes.
Further research is needed to clarify the variable effects of niacin in different populations and its role as an NAD modulator versus a lipid-lowering agent in reducing long-term health risks.