Tryptophan is an essential α-amino acid that plays a crucial role in the biosynthesis of proteins and is a precursor to the neurotransmitter serotonin, the hormone melatonin, and vitamin B3
. It is a polar molecule with a non-polar aromatic beta carbon substituent and is found in both plant and animal-based protein sources
. Tryptophan is necessary for normal growth in infants and is required for the production and maintenance of the body's proteins, muscles, enzymes, and neurotransmitters
. Some key functions of tryptophan include:
- Protein synthesis: Tryptophan is a constituent of protein synthesis and is found in the lowest concentrations among the amino acids, making it relatively less available
- Serotonin synthesis: Tryptophan is the sole precursor of serotonin, which is involved in regulating appetite, sleep, mood, and pain
- Melatonin synthesis: Tryptophan is also a precursor to melatonin, which helps regulate the sleep-wake cycle
- Niacin production: The liver can use tryptophan to produce niacin (vitamin B3), which is needed for energy metabolism and DNA production
Foods high in tryptophan include chicken, eggs, cheese, fish, milk, sunflower seeds, peanuts, pumpkin seeds, sesame seeds, soybeans, turkey, tofu, and almonds
. To convert tryptophan into niacin, the body needs enough iron, riboflavin, and vitamin B6
. Tryptophan supplements are available in powder form and can be taken orally, but it is essential to consult a healthcare professional before using them
