High-Dose Niacin Linked to Increased Heart Disease Risk, Study Warns

A new study in Nature Medicine has raised concerns about high doses of niacin, a common vitamin also known as B3. While it has long been used to lower cholesterol, researchers now warn that excessive amounts may increase the risk of heart disease. The findings suggest that too much niacin could harm blood vessels instead of protecting them. Niacin plays a vital role in the body, supporting energy metabolism, DNA repair, and antioxidant defence. It is naturally found in foods like chicken, salmon, sunflower seeds, and fortified cereals. The recommended daily intake is 16 mg for men and 14 mg for women.

The study identified a byproduct called 4PY, which forms when niacin levels are too high. This substance triggers inflammation in blood vessels, potentially leading to atherosclerosis—a condition linked to heart attacks and strokes. Historically, doctors prescribed niacin in doses of 500 to 1,000 mg to lower cholesterol, but the new research questions this practice. Dr. Cheng-Han Chen, a medical expert, has advised caution with routine niacin supplementation. While low doses offer benefits—such as improved skin health and neurological function—high intake may now pose risks. Health authorities recommend getting niacin from food rather than supplements and consulting a doctor before continuing high-dose regimens.

The study’s findings highlight a need for careful niacin use, particularly for those taking supplements. People currently on niacin medication should speak with their healthcare provider to assess potential risks. For most, obtaining the vitamin through a balanced diet remains the safest approach.