Niacin
Component of the cell building block NADP (nicotinic acid dicucleotide). Plays a particularly important role in hydrogen transport and biological oxidation.
Abbreviation for nicotinic acid or nicotinic (acid) amide, which are biologically equivalent.
Normally sufficient self-synthesis from the essential amino acid tryptophan. However, this presupposes that tryptophan is present in excess, i.e. that it is not used for protein synthesis.