Niacin (Vitamin B3) – Scientific Review on Usage & Dosage What is vitamin B3? Vitamin B3, also known as niacin, is actually made up of niacin (nicotinic acid) and niacinamide. It is a water-soluble nutrient that is part of the B vitamin family. B vitamins help to support adrenal function, to calm and maintain a healthy nervous system, and are necessary for key metabolic processes. Niacin is essential for the metabolism of carbohydrates and fats.…"Niacin (Vitamin B3) – Scientific Review on Usage & Dosage"