Is their any bad side efects from taking to much of the supplement vitimin niacin and how much should be taken a day ?

Not Medical Advice: Yes. Niacin overdose may cause nausea, dizziness, itching, vomiting, upset stomach, and flushing. Recommended daily allowance of ...More?

Monday, February 06 2012
Source: http://www.drugs.com/niacin.html