Phenylalanine Requirements in Healthy Pregnant Women

Overview

Phenylalanine is an essential amino acid that people need to obtain in their diets. Amino acids are the building blocks for protein, which is required to form tissues in the body. It is well known that pregnant women require more protein in their diets, but the exact amount for each amino acid is undetermined. To find out how much of phenylalanine pregnant women require, the investigators plan to study pregnant women in early and late gestation with a modern minimally invasive technique.

Full Title of Study: “Dietary Phenylalanine Requirements During Different Stages of Gestation in Healthy Pregnant Women”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: N/A
    • Intervention Model: Single Group Assignment
    • Primary Purpose: Basic Science
    • Masking: None (Open Label)
  • Study Primary Completion Date: May 30, 2018

Detailed Description

The investigator's purpose is to determine the phenylalanine requirements in healthy pregnant women as part of a Master's Thesis project. The determined requirements can be taken into account when giving dietary recommendations, to ensure healthy pregnancies. The hypothesis is that the current recommendations for phenylalanine intake given to pregnant women are underestimated. The investigators also hypothesize that the phenylalanine requirements at early stages of pregnancy will be lower than the requirements towards the later stages of pregnancy. Current dietary intake recommendations for phenylalanine are based on factorial (mathematical) calculations and do not account for requirement differences between early and late pregnancy. Static recommendations throughout all stages of pregnancy are not appropriate because of the multitude of adaptations the human body goes through during gestation. Whether phenylalanine requirements differ between different stages of gestation is unknown. In addition, phenylalanine is the precursor for tyrosine, which is a conditionally indispensable amino acid. Together they are referred to as the aromatic amino acids. The DRI gives a recommendation for total aromatic amino acids (TAA, phenylalanine + tyrosine) of 36 mg/kg/d during pregnancy. Since this study is the first interested in phenylalanine requirements during pregnancy, the investigators will determine the phenylalanine requirements in the presence of excess tyrosine (61 mg/kg/d) during pregnancy, similar to earlier studies. The investigators will recruit healthy pregnant women aged 20 to 40 in their 13th-19th week of gestation or 33rd to 39th week of gestation. Once they get in contact with the lab, an initial visit (pre-study) will take place. Here, the participants will be measured for their eligibility and taken through the consent form. They have to participate in a pre-study for each stage of pregnancy, if they wish to participate in both stages. If they meet all the criteria and agree to participate, they will return for up to two study days per stage of 8 hours each. Therefore, if they are recruited during late pregnancy they are only able to participate in two study days in total. During these study days they will be fed protein shakes containing the stable isotope, and then oxidation of this isotope will be measured to determine a breakpoint (requirement) of phenylalanine. Breath samples, urine samples, and a small blood sample will be taken during the study day.

Interventions

  • Dietary Supplement: Phenylalanine 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.

Arms, Groups and Cohorts

  • Other: Experimental: phenylalanine intake
    • Dietary supplement: phenylalanine intake

Clinical Trial Outcome Measures

Primary Measures

  • 13C Phenylalanine Oxidation
    • 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.

Participating in This Clinical Trial

Inclusion Criteria

  • over the age of twenty – under the age of forty – in overall good health – pregnant with a single child Exclusion Criteria:

  • Be under the age of twenty – Be over the age of forty – Be pregnant with more than one child – Have a history of cardiovascular disease, endocrine disorders, or metabolic disorders – Have recently lost a substantial amount of weight – Delivered a baby in the last 18 months – Be substance dependent – Be allergic to eggs – Have severe nausea through the pregnancy – Have gestational diabetes – Have a history of spontaneous abortions – Have had an unhealthy pre-pregnancy body mass index

Gender Eligibility: Female

Minimum Age: 20 Years

Maximum Age: 40 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • University of British Columbia
  • Collaborator
    • Canadian Institutes of Health Research (CIHR)
  • Provider of Information About this Clinical Study
    • Principal Investigator: Rajavel Elango, PhD, Principle Investigator – University of British Columbia
  • Overall Official(s)
    • Rajavel Elango, Ph.D., Principal Investigator, University of British Columbia

Clinical trials entries are delivered from the US National Institutes of Health and are not reviewed separately by this site. Please see the identifier information above for retrieving further details from the government database.

At TrialBulletin.com, we keep tabs on over 200,000 clinical trials in the US and abroad, using medical data supplied directly by the US National Institutes of Health. Please see the About and Contact page for details.