One Vitamin That “Opens Blood Vessels” and Improves Circulation

The vitamin usually being referred to in headlines like this is niacin (vitamin B3).

Niacin—specifically nicotinic acid—can cause temporary widening of small blood vessels, producing the familiar “niacin flush”: warmth, redness, tingling and itching. (Office of Dietary Supplements)

But there’s an important catch

That flushing effect doesn’t mean niacin is a safe or effective treatment for poor circulation. Research on whether niacin meaningfully improves blood-vessel function has been mixed. (PubMed)

High-dose niacin can also cause liver problems, increased blood sugar, gout, low blood pressure and other adverse effects. Current evidence doesn’t show that adding niacin to a statin provides additional protection against heart attacks or strokes for most people. (MedlinePlus)

In fact, NIH-funded research has raised concerns that excess niacin and its metabolites may contribute to cardiovascular risk. (National Institutes of Health (NIH))

🥗 The safer approach

Most people can get enough vitamin B3 from foods such as fish, poultry, meat, peanuts, legumes and fortified grains. (MedlinePlus)

If you’re experiencing cold feet, numbness, leg pain when walking, swelling or other circulation problems, don’t try to treat them with high-dose niacin. Those symptoms can have several causes and deserve proper evaluation.

Bottom line: Yes, vitamin B3 (niacin) can temporarily dilate small blood vessels, but that doesn’t make high-dose niacin a general “circulation booster.” Don’t take large doses for this purpose without medical supervision.