When the diet contains an adequate amount of protein, what amino acid can be used by the body to synthesize niacin?

a. phenylalanine

b. valine

c. glycine

d. tryptophan

e. lysin?

Niacin is another name for nicotinic acid. It is an organic compound that is synthesized in the liver. The essential amino acid that is utilized to synthesize niacin is tryptophan. To make 1 mg of niacin, your body needs 60mg of tryptophan. The biosynthesis of niacin requires riboflavin as well and vitamin B6.

The answer is D.