Methionine Requirements During Healthy Human Pregnancy

February 9, 2026 updated by: Rajavel Elango, PhD, University of British Columbia
The current recommendations for dietary amino acid intake in pregnant women are based on calculations from requirements of adult men. The study aims to determine methionine requirements during early (11-20 weeks) and late (31-38 weeks) stages of pregnancy. Methionine, an essential amino acid (building block of body protein), is necessary for protein synthesis and for DNA related cellular functions. A non-invasive, novel method based on different diets, stable isotopes (the safe kind) and simple breath collection will be used. This method has recently been used by our laboratory to study other amino acids during pregnancy.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Pre-study day protocol:

Participants will be asked to meet for a brief (1 hour) pre-study assessment in preparation for the study day. Participants' eligibility will be assessed during this time. Subjects will arrive at the British Columbia Children's Hospital Research Institute's Clinical Research and Evaluation Unit (CREU) having fasted overnight (at least 8 hours since last caloric intake; no morning exercise, and assisted transportation to minimize stress). The consent form will be thoroughly explained, with the subject instructed to stop and ask questions at any point in which they are confused or uncomfortable. If the participants are willing to participate, verbal consent and a signature will be obtained. On this day, participants will fill out a questionnaire, and the following measurements will be taken: height (Harpenden Stadiometer; Holtain Limited, UK) and weight (electric scale; HealthOMeter Professional, Sunbeam Products, Inc.), bioelectrical impedance analysis (BIA; Q4 Bioimpedance Analyzer, RJL Systems, MI), 3 site skinfold (Harpenden Calipers; Baty International, UK), blood glucose (One Touch Ultra, LifeScan, Inc.), and resting energy expenditure (REE; Vmax Encore, Viasys, CA). The REE describes the caloric requirement for vital function in the absence of physical exertion. This value will be used to calculate the total energy content of the experimental diets in order to ensure that the specific caloric needs of each participant will be met. Blood glucose will be assessed for gestational diabetes mellitus (GDM; fasting plasma glucose level of 5.3 mmol/L indicative of GDM). Skinfold and BIA measurements will be collected to determine maternal fat and fat free mass.

Study day protocol:

Healthy pregnant women (20-40 y) who have consented and participated in the pre-study day will be studied at two stages of gestation (n=15/stage) over a range of test methionine intakes (ranging from 0-40mg/kg/day). At the beginning and end of the day a urine dipstick test will be performed. Each study day will be separated by a week and will receive a different, random methionine test intake. On the day of the study, participants will come in fasted at ~8 am for a total of eight hours. They will receive eight hourly meals, which represent 1/12 of their balanced nutritional need for the day. The meals consist of an orange flavoured shake with egg protein composition, balanced with sufficient carbohydrates and lipids. A tracer amino acid (L-[1-13C] phenylalanine) will be provided with the test meals to assess oxidation of the tracer to 13CO2 (13C- carbon dioxide) in breath in response to the test/limiting amino acid (methionine). Open-circuit indirect calorimetry will be performed until 5 steady state data points will be obtained for the measurement of VCO2 (Carbon Dioxide Output; Vmax Encore, Viasys, CA). This technique, called the indicator amino acid oxidation method, is a novel, non-invasive and completely safe approach especially in pregnancy.

Throughout the 8-hour study period biological samples (breath, urine, blood) will be collected and analyzed for 13CO2 content and sulfur amino acid metabolites.

Study Type

Interventional

Enrollment (Actual)

69

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • British Columbia
      • Vancouver, British Columbia, Canada, V5Z4H4
        • BC Children's Hospital Research Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

20 years to 40 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Women who are 20-40 years of age. This includes women of reproductive age who have a low relative risk ratio of maternal or neonatal morbidities.
  2. Women pregnant with a singleton pregnancy.
  3. Women who are 11-20 or 31-40 weeks pregnant.
  4. In apparently good health. Subjects must not have pre-existing health conditions.

Exclusion Criteria:

  1. Women who are not pregnant or who are pregnant with more than one fetus.
  2. Women who were pregnant in the 6 months before the current pregnancy
  3. Women with history of spontaneous abortion (within the last 6 months) or pre-term birth
  4. Women who are younger than 20 years of age and older than 40 years of age.
  5. Women with a metabolic, neurological, genetic or immune disorder likely to affect nutritional requirements or overall body metabolism.

5. Women who depend on medication that affects normal metabolism. 6. Women experiencing severe nausea, food avoidance or vomiting throughout their pregnancy.

7. Women allergic to eggs or egg protein. 8. Women classified as underweight (<18.5 kg/m2), overweight (25-30 kg/m2) or obese (>30 kg/m2).

9. Women smoking cigarettes, taking illicit drugs, or consuming alcohol regularly during their pregnancy.

10. Women who do not take a prenatal vitamin for the duration of their study period.

11. Women who have lost weight (approximately 1.5kg or more) during their current pregnancy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Methionine Intake
Oral consumption of eight hourly experimental meals- Includes 4 tracer-free experimental meals containing a mixture of free amino acids, calories from a flavored liquid and protein free cookies and 4- labeled amino acid experimental meals.
Dietary supplement: Methionine Intake
Intakes will be randomly chosen from a list of 7 doses of methionine. Each intake will will be repeated approximately 5 times.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The rate of oxidation of 13C phenylalanine.
Time Frame: 8 hours
Urine, breath and a single blood sample will be collected during the study to measure the rate of oxidation of 13C phenylalanine.
8 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of British Columbia

Investigators

  • Principal Investigator: Rajavel Elango, PhD, University of British Columbia

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 14, 2020

Primary Completion (Actual)

June 21, 2023

Study Completion (Actual)

June 1, 2024

Study Registration Dates

First Submitted

March 26, 2020

First Submitted That Met QC Criteria

March 27, 2020

First Posted (Actual)

March 30, 2020

Study Record Updates

Last Update Posted (Actual)

February 12, 2026

Last Update Submitted That Met QC Criteria

February 9, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • H20-00383

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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