Tryptophan Requirements During Pregnancy

NCT06519071 | Completed

• 1 other identifier: H23-01187
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

Pregnancy is an important period of life where there is an increased need for nutrients including protein and amino acids from food. The current protein and amino acids dietary recommendations were all established using older methods done in adult men. Then protein and amino acids requirements for all stages of pregnancy were calculated without accounting for changing demands in each trimester. Therefore, another more precise method is needed to better understand how much amino acids (in this study tryptophan) women need during pregnancy. In the current study, the investigators are going to apply the Indicator Amino Acid Oxidation (IAAO) method to measure the dietary tryptophan needs in a healthy pregnancy. This method is a noninvasive, quick, and reliable technique that uses a stable isotope-labeled amino acid. The stable isotope tracer is a labeled amino acid, which is colorless, odorless, tasteless, and completely safe; they are present in the air, water and food. Amino acids are mostly made of Carbon-12 (12C), whereas the isotope tracer contains Carbon-13 (13C). The tracer can be detected in breath and urine samples with special equipment because it looks different than the rest of the amino acids in the body. In Elango lab, the investigators have done similar studies, using the same technique in children, nonpregnant women and pregnant women. This will allow us to measure tryptophan needs in pregnancy.

Conditions

Pregnancy

Keywords

Amino Acids; Tryptophan; Pregnancy; Indicator Amino Acid Oxidation; Stable Isotopes

Outcome Measures

Primary Outcomes (1)

• Carbon 13 Oxidation

  Urine and breath will be collected to measure the rate of oxidation of L-\[1-13C\]phenylalanine oxidation.

  8 hours

Study Arms (1)

Tryptophan Intake

EXPERIMENTAL

Randomly assign the participant to receive a test tryptophan oral intake (ranging between 1 to 14 mg.kg.d) as an 8-hourly isocaloric and isonitrogenous meal that consist of a liquid formula shake and protein-free cookies.

Other: Tryptophan Intake

Interventions

Tryptophan Intake OTHER

Each hourly meal will provide one-twelfth of the participants' daily energy requirements as estimated by 1.7 Resting Energy Expenditure and adequate protein (at 1.5 g.kg.d), to maintain a metabolic steady state. The liquid shake contains protein-free powder orange-flavored drink crystals, corn oil, and water.

Tryptophan Intake

Eligibility Criteria

• Age: 20 Years - 40 Years
• Gender Eligibility Details: Cis-women.
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Cis-gendered pregnant woman.
• years of age.
• Pregnant with a single child.
• Between 11-20 weeks of gestation or 31-40 weeks of gestation.
• Free of chronic diseases/acute diseases and have a full range of physical mobility.

You may not qualify if:

• Women who are not pregnant.
• Women who are pregnant with more than one child (this changes amino acid demands) or were pregnant in the 6 months before the current pregnancy.
• Women with a history of spontaneous abortion (within the last 6 months) or preterm birth.
• Women not in good health or have a metabolic, cardiovascular, neurological, genetic, or immune disorder, including gestational diabetes, preeclampsia, pregnancy-related anemia, or pregnancy-related jaundice.
• Claustrophobic women (a clear hood will be placed, which can easily be removed, over the participants head for approximately 20 min to measure energy expenditure).
• Women who are substance dependent (i.e., alcohol, tobacco, illicit drugs).
• Women who have severe nausea/vomiting throughout their pregnancy.
• Women under the age of 20 years and over the age of 40 years.
• Women who have lost weight (approximately 1.5kg or more) during their current pregnancy.
• Women with a pre-pregnancy Body Mass Index (BMI) under 19 or over 28 〖kg/m〗\^2.

Sponsors & Collaborators

• University of British Columbia: lead
• Canadian Institutes of Health Research (CIHR): collaborator

Study Sites (1)

BC Children's Hospital Research Institute, University of British Columbia

Vancouver, British Columbia, V5Z4H4, Canada

Location

Study Officials

• Rajavel Elango, PhD

  University of British Columbia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: August 2, 2023
• First Posted: July 25, 2024
• Study Start: July 20, 2023
• Primary Completion: March 20, 2025
• Study Completion: July 18, 2025
• Last Updated: September 16, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)