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Tryptophan

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.

Function

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:

  • Iron
  • Riboflavin
  • Vitamin B6

Food Sources

Tryptophan can be found in:

  • Cheese
  • Chicken
  • Eggs
  • Fish
  • Milk
  • Nuts
  • Peanut butter
  • Peanuts
  • Pumpkin seeds
  • Sesame seeds
  • Soy
  • Tofu
  • Turkey

References

Parker G, Brotchie H. Mood effects of the amino acids tryptophan and tyrosine: 'Food for Thought' III. Acta Psychiatr Scand. 2011;124:417-426. PMID: 21488845 www.ncbi.nlm.nih.gov/pubmed/21488845.

U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015-2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at http://health.gov/dietaryguidelines/2015/guidelines/. Accessed January 15, 2016.

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Update Date 5/9/2014

Updated by: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Editorial update 01/15/16.