High levels of niacin, a B-group vitamin considered essential, may increase the risk of heart disease by triggering inflammation and damaging blood vessels, according to a new study published today in Nature Medicine. The study revealed a previously unknown risk associated with excessive amounts of the vitamin, which is found in many foods, including meat, fish, nuts, and fortified cereal products like bread.

The recommended daily dose of niacin for men is 16 milligrams per day, and for non-pregnant women, it is 14 milligrams per day. Approximately 1 in 4 Americans has higher than recommended levels of niacin, stated the study’s lead author, Dr. Stanley Hazen, head of metabolic and cardiovascular sciences at the Cleveland Clinic’s Lerner Research Institute and head of preventive cardiology at the Heart, ...