The term ‘niacin’ is used as a generic description of nicotinic acid and nicotinamide with pyridine as the basic structure. Nicotinic acid and nicotinamide function mainly as precursors of the co-enzymes NAD and NADP. Thus, nicotinamide has physiologically critical roles in mitochondrial respiration and in the metabolism of carbohydrates, lipids, and amino acids. Oral administration routes of nicotinamide via feed or water for drinking are considered bioequivalent. Nicotinamide is safe for the target animals with a margin of safety that is at least ten times the requirements and use levels. The FEEDAP Panel assumes that exposure figures for a population already include the contribution of edible tissues and products of animals fed niacin-supplemented diets. Information on niacin metabolism and the limited data available on retention in edible tissues and products indicate that supplemental levels in feeds even far higher than the requirements (1–35 mg/kg feed) are highly unlikely to lead the tolerable upper intake level being exceeded. The FEEDAP Panel considers that the use of nicotinamide in animal nutrition is not of safety concern for consumers. Nicotinamide is not irritant to skin, but can cause irritancy to eyes and mucous membranes. It is unlikely to cause skin sensitisation. Workers might be exposed to a respirable dust when handling nicotinamide, which should be regarded as being potentially harmful to their health. The use of nicotinamide in animal nutrition does not pose a risk to the environment. Nicotinamide is regarded as an effective source of niacin in animal nutrition.