Tryptophan is an amino acid needed for normal growth in infants and for nitrogen balance in adults. It is an essential amino acid, which means your body cannot produce it -- you must get it from your diet.
The body uses tryptophan to help make niacin and serotonin. Serotonin is thought to produce healthy sleep and a stable mood.
In order for tryptophan in the diet to be changed into niacin, the body needs to have enough:
Dietary Guidelines for Americans - 2005. Washington, DC. US Dept of Health and Human Services and US Dept of Agriculture: 2005.
Linda Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.