The vitamin most often associated with blood-vessel widening (vasodilation) is niacin (vitamin B3). Specifically, nicotinic acid can cause flushing because it temporarily dilates small blood vessels in the skin.
But there is an important catch: that flushing does not mean niacin is a good treatment for poor circulation. High-dose niacin can cause headaches, dizziness, low blood pressure, liver problems, increased blood sugar, and other adverse effects.
Don’t take high-dose niacin just to “open your arteries”
Modern cardiovascular guidance does not recommend over-the-counter supplements as a general way to prevent cardiovascular events, and adding niacin to statin therapy has not been shown to provide additional cardiovascular benefit in clinical trials.
If you have cold feet, numbness, leg pain when walking, swelling, or wounds that heal slowly, the underlying cause should be evaluated rather than treated with a vitamin.
Bottom line: Niacin can cause temporary vasodilation, but it isn’t a safe “circulation booster” to take in large doses. If circulation is a concern, finding the cause—such as peripheral artery disease, diabetes, anemia, or medication effects—is much more important.
