Is Too Much Niacin in Your Diet Bad for You?

Limiting processed foods could help avoid niacin overload

Niacin deficiencies were more common in the U.S. in the early 20th century around the time of the Great Depression. By the 1970s, niacin deficiencies and the complications that ensued — a disease known as pellagra — had become rare, says Hazen, chair of cardiovascular and metabolic sciences at Cleveland Clinic’s Lerner Research Institute.

“And that’s because so many things are fortified,” he explains. “[Niacin] literally is put in the flour we eat, the rice, the oats, the cereal.”

Americans are eating more of these products than ever, increasingly relying on ultra-processed foods, “much of which include refined fortified flour and cereals,” the study’s authors note. Niacin is also sold as a supplement and was once a go-to prescription treatment for high cholesterol, though research suggests it doesn’t add much benefit to statin therapy and can cause harmful side effects.

Among the two groups of patients included in this latest study, 1 in 4 had high levels of niacin that could be linked to increased heart risks, Hazen says. The Office of Dietary Supplements at the National Institutes of Health says most people in the United States consume more than the recommended daily intake for niacin, which is 16 milligrams (mg) a day for men and 14 mg for women.

Given the results of the study, Hazen says people should talk to their doctor before taking an over-the-counter supplement. Research from AARP shows that nearly 80 percent of adults 50 and older take a vitamin or dietary supplement.

“The second thing I would say is to just focus on a diet rich in fruits and vegetables and avoid excess carbohydrates,” Hazen says. Approximately 60 percent of the American diet comes from processed foods, studies show.

Another possible outcome of the research is a larger conversation around the fortification of foods, especially as medicine evolves to become more tailored to each individual patient’s needs.

“Should there be [a nonfortified] option made available to people? Because right now it’s just one size fits all,” Hazen says. “At the time, it made a tremendous health benefit to a nation that was starving, essentially. But we’re not that same nation anymore.”