Nicotinamide (NA) is one form of niacin. A deficiency of this vitamin leads to loss of copper from the body, known as pellagra disease. Victims of pellagra show unusually high serum and urinary copper levels (Krishnamachari, 1974 ▸). The NA ring is the reactive part of nicotinamide adenine dinucleo­tide (NAD) and its phosphate (NADP), which are the major electron carriers in many biological oxidation-reduction reactions (You et al., 1978 ▸). The nicotinic acid derivative N,N-di­ethyl­nicotinamide (DENA) is an important respiratory stimulant (Bigoli et al., 1972 ▸).