Common Vitamin Supplement Could Increase Risk of Heart Disease

By: Chris Gorrie | Published: Mar 01, 2024

In recent research led by the Cleveland Clinic, a significant association between excess Vitamin B3 (niacin) intake and an increased risk of heart disease has been uncovered. 

Published in the journal Nature Medicine, the study reveals that up to 25% of individuals may have higher-than-recommended niacin levels. While niacin, also known as Vitamin B3 or nicotinic acid, was once suggested for cholesterol reduction, this study sheds light on its potential adverse effects on cardiovascular health.

Niacin Causes Inflammation in the Circulatory System

Upon breaking down niacin, the body produces a byproduct called 4PY, initiating inflammation in the circulatory system. 

A close-up image of someone’s stomach. There is a red rash across their mid torso. The rash is caused by niacin use.

Doc James/Wikimedia Commons

This inflammation damages blood vessels and contributes to the formation of atherosclerosis, a buildup that significantly elevates the risk of strokes, heart attacks, and other major heart issues. 

The Average Person Should Avoid Niacin Supplements

The study’s senior author, Stanley Hazen, emphasizes the importance of avoiding niacin supplements for the average person due to the potential increased risk of cardiovascular disease.

Bottles and boxes of dietary supplements stacked on shelves and display stands inside a store.

Tiia Monto/Wikimedia Commons

“[W]e have reason to believe that taking too much niacin can potentially lead to an increased risk of developing cardiovascular disease,” Hazen said in a recent statement.

Investigating Unknown Risks Associated with Heart Disease

The researchers initiated the study to investigate unknown risks associated with heart disease. 

A scientist stands over a blue drawer holding a scalpel and a small card with information written on it.

National Cancer Institute/Unsplash

A major motivation behind this study is the persistence of heart disease in individuals adhering to recommended preventive measures

Preventive Measures for Heart Disease

What are the preventive measures recommended to combat the onset of heart disease?

A person’s feet on a scale.

Source: i yunmai/Unsplash

They include eating a healthy diet, getting regular exercise, limiting alcohol consumption, and effectively managing weight, blood pressure, and blood sugar. Heart disease stands as the leading cause of death in the U.S., contributing to 1 in 5 deaths in 2021.

Study Methodology and Results

The newly published study involved the analysis of blood samples from several thousand individuals.

A scientist wearing blue gloves and protective glasses looking at a blood sample in a vial.

Source: National Eye Institute/Wikimedia Commons

Initially, the analysis of blood samples focused specifically on people being monitored for heart problems, but it was later expanded to a broader population.


The Niacin Paradox: Lowering Cholesterol with Adverse Effects

In all cases, the analyses consistently indicated a higher risk of heart problems associated with elevated niacin levels. 

A person’s hand next to a blood sugar monitoring device insulin, and fruit.

Ofek Abuhazira/Wikimedia Commons

These findings offer insights into the “niacin paradox,” a phenomenon where niacin’s cholesterol-lowering benefits are overshadowed by adverse effects, including an increased risk of diabetes, brain bleeding, skin problems, and gut issues.


New Study Shows Niacin’s Adverse Effects Outweigh Benefits

The research demystifies the niacin paradox and clarifies why clinical benefits were often less than anticipated based on LDL reduction. 

A 3D rendering of a human heart and the surrounding parts of the circulatory system.

Bryan Brandenburg/Wikimedia Commons

Despite niacin’s ability to lower cholesterol, its unclear adverse effects seemed to counteract the expected benefits. Senior author Hazen notes that understanding residual cardiovascular risk is crucial, as it provides valuable insights beyond the initial research goals.


Niacin was Once Used to Combat Pellagra

Niacin, historically added to products like flour and fortified cereals since the Great Depression era, aimed to combat pellagra—a health condition resulting from niacin deficiency. 

Two illustrations showing the effects of pellagra on someone’s hands.

Wellcome Images/Wikimedia Commons

Pellagra symptoms include skin problems, diarrhea, and dementia, which shows the importance of niacin fortification during that period.


Niacin Deficiency in the Great Depression

During the Great Depression, pellagra impacted over 3 million Americans, and resulted in over 100,000 deaths. As noted above, the epidemic saw resolution through dietary niacin fortification. 

Black-and-white photo of unemployed men standing in a large line wearing coats, suits, and hats. They are waiting for free soup and coffee. It is 1931 in the midst of the Great Depression.

National Archives at College Park/Wikimedia Commons

Particularly prevalent in the American South, pellagra ranked as the ninth or tenth leading cause of death, boasting a death rate comparable to malaria.


A Nuanced Approach to Niacin Intake

Hazen suggests a nuanced approach to niacin intake, emphasizing the need for a discussion regarding the continued fortification of flour and cereals with niacin in the U.S.

Oats, barley, a loaf of sliced bread, a loaf of unsliced bread, flour, and cookies.

Peggy Greb/Wikimedia Commons

Hazen stated that “Given these findings, a discussion over whether a continued mandate of flour and cereal fortification with niacin in the U.S. could be warranted.”


More Balanced Approach to Niacin Intake is Necessary

The research clearly displays the potential cardiovascular risks associated with excessive niacin intake, challenging previous perceptions of its benefits in cholesterol management. 

An Avery scale sitting in front of a large window.

Piret Ilver/Wikimedia Commons

As discussions evolve regarding the fortification of everyday products, the study contributes to our understanding of the complex relationship between niacin and heart health, emphasizing the need for balanced approaches to dietary supplementation.