In Southern State of America pellagra was the second most common cause of death till 1915 to 1916. Goldberger came close to solve the problem but it was not until 1937 that R. J. Madden used niacin successfully to treat pellagra. It can be formed from the essential amino-acid tryptophan. In human 1 mg niacin is formed fro 60 gm dietary tryptophan. Niacin or nicotinic acid is rapidly converted in the body to nicotinamide which is a component of coenzyme, essential for the metabolism of carbohydrates, fats and protein. It is water soluble, but comparatively resistant to heat. Cooking causes little destruction of niacin but considerable amount is lost if the cooking water and 'drippings' from cooked meat are discarded. In a mixed diet 15 to 25% of the niacin is lost this way. Liver ground nut, pulses, meat and fish are good sources of niacin. In many cereals especially maize the vitamin occurs in a bond in unabsorbable form known as 'Niacytin'. Milling may remove most of the niacin from cereal. Recommended daily allowances of niacin are 6.6 mg / 100 Kcal. Pellagra is a nutritional disease endemic among poor peasants fed on maize. The greater part of niacin in maize is in bond form i.e. , Niacytin, which is not available to the consumer. More over the principal protein of maize, zein is deficient in the essential amino acid tryptophan the alternative sources niacin.
