Niacinamide, known as nicotinamide, is an important compound functioning as a component of the coenzyme NAD. Its primary significance is in the prevention and/or cure of blacktongue and pellagra. Pellagra is a nutritional disease that occurs due to insufficient dietary amounts of vitamin B3 or the chemical it is made from (tryptophan). Symptoms of pellagra include skin disease, diarrhea, dementia, and depression. In addition, was experiments, revealed, that niacinamide hydroiodide might have role in ophthalmology and parenteral use of niacinamide hydroiodide can treat arteriosclerotic syndromes.