What is a common side effect of Niacin (B3)?

Niacin, also known as vitamin B3, is commonly associated with flushing and itching as side effects, particularly when taken in higher doses than typically found in dietary supplements. This flushing is caused by the release of prostaglandins, which are compounds that cause blood vessels to dilate and can lead to the sensation of warmth, redness of the skin, and discomfort. Itching may also occur as a result of this vasodilatory effect.

While other side effects like headaches, nausea, and constipation can occur with various medications and supplements, they are not as characteristic or common when it comes to niacin. Flushing is a distinctive side effect that is often noted in clinical discussions about niacin and is something healthcare providers routinely warn patients about when prescribing or recommending it, especially in therapeutic doses.