Niacin, (which is also known as nicotinic acid or vitamin B3), is a water-soluble vitamin. Nicotinamide is the metabolite of niacin and used by the body to form the coenzymes nicotinamide adenine dinucleotide phosphate (NADP) and nicotinamide adenine dinucleotide (NAD). None of the forms are related to the nicotine found in tobacco, although their names are similar.
Living organisms derive a great portion of their energy from oxidation-reduction (redox) reactions, transferring electrons. About 200 enzymes require the niacin coenzymes, NAD and NADP, to accept or donate electrons in redox reactions. NAD functions most often in energy producing reactions involving the catabolism of carbohydrates, fats, proteins, and alcohol. NADP functions more often in anabolic reactions, such as in the synthesis of all macromolecules, including fatty acids and cholesterol.
Recommended Dietary Allowance (RDA) for Niacin varies with age and sex. Generally, all infants regardless of sex and under the age of 6 months require a daily intake of niacin of 2 mg (milligrams); from 6 months to 1 year 4 mg daily. 1–3 years, 6 mg; 4-8 8 mg; 9-13 12 mg; 14 and older males 16 mg, females 14 mg unless pregnant or breastfeeding which raises the requirement to 18 mg.