Vitamin A Kinetics and Mathematical Modeling in American Women

Women were given a vitamin A tracer, and blood was sampled to determine individual and group vitamin A kinetics. Data were subsequently modeled using compartmental analysis to determine effects of study length on model outcomes.

Study Overview

• Status: Completed
• Conditions: Vitamin A Kinetics
• Intervention / Treatment: Other: Vitamin A tracer

Detailed Description

This is a longitudinal study in which American women were given an oral, stable isotope tracer of vitamin A, and blood was sampled in a staggered, serial design to determine individual and group vitamin A kinetics. Data were subsequently modeled using compartmental analysis, and study truncation analysis was performed on data to investigate the factor of study duration on resulting vitamin A kinetic models and outputs related to vitamin A metabolism.

• Study Type: Interventional
• Enrollment (Actual): 8
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53706
      • Department of Nutritional Sciences, University of Wisconsin-Madison

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 30 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• BMI (18.5 - 24.9 kg/m2)

Exclusion Criteria:

• Smoker
• Pregnant
• Trying to become pregnant
• Lactating
• Weight loss > 4.5 kg during the past 3 months.
• Actively trying to lose weight
• Inability to refrain from drinking alcohol when requested
• Amenorrhea
• Acute or chronic illness including hepatitis
• Current or previous history of anorexia or bulimia
• Concurrent participation in other studies
• Family member already enrolled in the study

Study Plan

How is the study designed?

Design Details

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

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Vitamin A tracer; A stable isotope tracer of vitamin A was given orally.	Other: Vitamin A tracer; A stable isotope tracer of vitamin A was given orally.; Other Names: 13C vitamin A; 13C retinyl acetate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total traced vitamin A mass	Total amount of endogenous vitamin A determined by mathematical model, (µmol).	Baseline through 152 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Compartmental model complexity	Required number of compartments in mathematical model needed to adequately fit data.	Baseline through 152 days
Compartmental model fractional transfer coefficients	Model parameters adjusted to fit analytical data. Represents the fractional transfer from one compartment to another in the model, (pools/d, represented as L(i,j), the fraction of compartment J transferred to compartment I per day).	Baseline through 152 days
Serum vitamin A half-life	Half-life of vitamin A in serum, (d).	Baseline through 152 days
Vitamin A disposal rate	Daily loss or utilization of vitamin A, (µmol/d).	Baseline through 152 days
Vitamin A equilibration time and partitioning	Time taken for vitamin A to equilibrate with body stores, (d).	Baseline through 152 days
Vitamin A tracer partitioning	Body partitioning of tracer between serum and extravascular compartment(s), relative to total tracee mass. Calculated as a ratio of tracer-to-tracee ratio (TTR) in serum and extravascular stores, (TTR serum / TTR stores).	Baseline through 152 days
Vitamin A dietary intake	Vitamin A dietary intake by food frequency questionnaire, (µg retinol activity equivalents/d).	Baseline

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Investigators: Principal Investigator: Sherry A Tanumihardjo, PhD, University of Wisconsin, Madison

Publications and helpful links

General Publications

• Gannon BM, Valentine AR, Davis CR, Howe JA, Tanumihardjo SA. Duration of Retinol Isotope Dilution Studies with Compartmental Modeling Affects Model Complexity, Kinetic Parameters, and Calculated Vitamin A Stores in US Women. J Nutr. 2018 Aug 1;148(8):1387-1396. doi: 10.1093/jn/nxy095.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2008
• Primary Completion (Actual): September 1, 2008
• Study Completion (Actual): October 1, 2016

Study Registration Dates

• First Submitted: August 8, 2017
• First Submitted That Met QC Criteria: August 11, 2017
• First Posted (Actual): August 14, 2017

Study Record Updates

• Last Update Posted (Actual): October 31, 2019
• Last Update Submitted That Met QC Criteria: October 29, 2019
• Last Verified: October 1, 2019

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Antineoplastic Agents; Immunologic Factors; Protective Agents; Micronutrients; Adjuvants, Immunologic; Antioxidants; Anticarcinogenic Agents; Vitamins; Vitamin A; Retinol palmitate; Retinol acetate
• Other Study ID Numbers: H-2008-0020; A074600 (Other Identifier: UW Madison); AG&LSC/NUTRITIONAL SCI/NUTRITI (Other Identifier: UW, Madison)

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