they are both b3.
niacinamide is niacin + amide.
the amide basically makes it slow release so no flush.
B3 deficiency = pellagra
some B3 deficiency characteristics
CNS: Dementia; Hyperreflexia; Startle myoclonus
? Neuropathy related to other associated vitamin deficiencies
read more at
http://neuromuscular.wustl.edu/nother/v ... htm#niacin
fyi b1 is thiamin. beri beri = B1 deficiency.