The Collaborative International Dictionary of English v.0.48:
niacinamide \niacinamide\ n. The amide of niacin (nicotinic acid), called also nicotinamide. It was at one time called vitamin B3, and can function to relieve nicotinic acid deficiency. Chemical formula C6H6N2O, chemically it is 3-pyridinecarboxamide. Syn: nicotinic acid amide, nicotinamide. [PJC]The Collaborative International Dictionary of English v.0.48:
vitamin B3 \vitamin B3\ n. See nicotinamide. Syn: nicotinamide. [PJC]