Original: When the biological significance of nicotinic acid was realized , it was thought appropriate to choose a name to dissociate it from nicotine , to avoid the perception that vitamins or niacin-rich food contains nicotine , or that cigarettes contain vitamins .
Simplified: When the properties of nicotinic acid were discovered , it was thought prudent to choose a name to dissociate it from nicotine , in order to avoid the perception that vitamins or niacin-rich food contain nicotine .