Determination of Lysine Requirements in Pregnancy


Amino acids are building blocks of protein in our body. It is important that pregnant women eat adequate amount of protein/amino acids to ensure healthy growth and development of the fetus.Lysine is an amino acid that is present in high amounts only in animal foods (meat) and not much in plant foods such as wheat. Currently , it is not known how much lysine is needed to eat during pregnancy. Current Dietary Reference Intake recommendations for amino acid requirements are based on non-pregnant adults, and minimally based on pregnancy-specific data.To the investigators knowledge, there is no scientific information regarding the amount of lysine needed at different stages of pregnancy. The investigators hypothesize that current recommendations for lysine intake in pregnant women are underestimated. The investigators also hypothesize that the lysine requirements will be greater during the later stages of pregnancy, compared to early stages. The purpose of this study is to determine lysine requirements in healthy pregnant women 19-40y,(1st and 3rd trimester) using a modern, safe and quick technique called the indicator amino acid oxidation technique and to compare lysine requirements during early (15-18 weeks last menstrual period) late (33-36 weeks last menstrual period) stages of pregnancy.

Full Title of Study: “Determination of Lysine Requirements in Healthy Pregnant Women Using the Indicator Amino Acid Oxidation Technique”

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: January 2014


  • Dietary Supplement: Lysine 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

  • Experimental: Lysine intake
    • Dietary supplement:lysine intake

Clinical Trial Outcome Measures

Primary Measures

  • 13 carbon dioxide production
    • Time Frame: 8 hours (1 study day)
    • Urine and breath samples will be collected during the study to measure the rate of oxidation of tracer in expired breath and flux by enrichment in urine.

Participating in This Clinical Trial

Inclusion Criteria

  • Singleton pregnancy – Maternal age 19-40y – Early stage of pregnancy(15-18 weeks) and late stage of pregnancy(33-36 weeks) – In good health (free of chronic/acute illness, full range of physical mobility) – Healthy pre-pregnancy body mass index Exclusion Criteria:

  • Subjects outside the age range of 19-40y – Women pregnant with more than one child – Body mass Index less than 18.5kg/m2 or greater than 25 kg/m2 – less than 18 months between current pregnancy and last pregnancy – History of spontaneous abortion,pre-term birth, preeclampsia/eclampsia, gestational diabetes, pregnancy-related anemia, pregnancy related jaundice – Existing metabolic disease – Substance dependance (i.e. alcohol, cigarette, illicit drugs) – Allergic to eggs and egg protein – Severe nausea and vomiting during pregnancy

Gender Eligibility: Female

Minimum Age: 19 Years

Maximum Age: 40 Years

Are Healthy Volunteers Accepted: No

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, PhD, Principal Investigator, Child & Family Research Institute/University of British Columbia

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