Dr. Michael Smith: Niacin, a B vitamin, has been prescribed for years to treat high cholesterol. Doctors often give it to patients along with statins to reduce the risk of heart disease. But a new study has noted serious concerns about it. The researchers found that although niacin does raise the “good” cholesterol and lower the “bad” cholesterol, it’s not reducing the risk of heart attack or stroke. And there’s bad news about side effects as well. Prescription-strength niacin is known to cause itching and flushing. But the study revealed the potential for more serious health issues. Those taking it had more diabetes, bleeding, infections, and liver problems. There are experts who dispute the study, but if you are taking niacin, it’s important that you talk to your doctor about it. And don't self-medicate with over-the-counter-niacin. For WebMD, I'm Dr. Michael Smith.