Introduction. 1  If you were a single-celled organism and you lived in a nutrient-rich place, staying alive would be pretty straightforward. 2  However, odds are you are not an amoebaâgiven that you're using Khan Academy right nowâand things arenât quite so simple for big, many-celled organisms like human beings.
The daily niacin requirement varies with the number of calories burned daily (the energy expenditure) and the protein intake. One niacin equivalent equals 1 mg of preformed niacin or 60 mg of dietary tryptophan. Niacin can be synthesized in the body from the essential amino acid tryptophan.Tissues can form an average of I mg of niacin from 60 mg of tryptophan provided by dietary protein. Consequently a high-quality protein diet supplies substantial tryptophan for niacin synthesis.he daily niacin requirement varies with the number of calories burned daily (the energy expenditure) and the protein intake. One niacin equivalent equals 1 mg of preformed niacin or 60 mg of dietary tryptophan. Niacin can be synthesized in the body from the essential amino acid tryptophan.
Niacin (also known as nicotinic acid, nicotinamide, niacinamide, vitamin B-3) is a B vitamin that is important in the normal functioning of the nervous system. Its commercial source is synthetic, and it may also be found in liver, yeast, meat, legumes, and whole cereals.equests from customers concerned about human-or animal-derived ingredients in their foods could also accelerate the use of synthetic L-cysteine in foods over feather-or human hair-derived L-cysteine. L-cysteine is considered a substance that is generally recognized as safe by the Food and Drug Administration.