High-dose niacin may harm heart health, new study warns

A new study has raised concerns about high doses of niacin, a common vitamin linked to heart health. Researchers found that excessive intake may increase the risk of heart disease by triggering inflammation in blood vessels. The findings challenge long-standing beliefs about niacin’s benefits for cholesterol management. The study, published in Nature Medicine, identified a substance called 4PY that forms when niacin is consumed in large amounts. This compound was shown to cause vascular inflammation, a key factor in atherosclerosis. High levels of 4PY were associated with a greater risk of heart attacks, strokes, and other cardiac events.

Niacin, also known as vitamin B3, plays a vital role in energy metabolism, DNA repair, and cell signalling. It is naturally found in foods like chicken, turkey, salmon, sunflower seeds, and fortified cereals. The recommended daily allowance is 16 milligrams for men and 14 milligrams for women—far below the doses used in some cholesterol-lowering treatments. For decades, niacin has been prescribed in doses of 500 to 1,000 milligrams to lower high cholesterol. While low doses support skin health, neurological function, and metabolism, the new research suggests that excessive supplementation may do more harm than good. Healthcare providers are now advising caution for patients using niacin for heart disease prevention.

The findings highlight the need for careful monitoring of niacin intake, particularly for those taking high-dose supplements. Patients currently using niacin for cholesterol management should consult their doctors before making any changes. The study underscores the importance of balancing vitamin intake to avoid unintended health risks.