Vitamin A Kinetics and Mathematical Modeling in American Women

Not Applicable

Completed

• Conditions: Vitamin A Kinetics
• Interventions: Other: Vitamin A tracer

• Registration Number: NCT03248700
• Lead Sponsor: University of Wisconsin, Madison

Brief Summary

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.

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 Timeline

• Study Start: 2008-03
• Primary Completion: 2008-09
• Study Completion: 2016-10
• Study First Submitted: 2017-08-08
• Study First Submitted QC: 2017-08-11
• Study First Posted: 2017-08-14
• Status Verified: 2019-10
• Last Update Submitted: 2019-10-29
• Last Update Posted: 2019-10-31

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 8

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Vitamin A tracer	Vitamin A tracer	A stable isotope tracer of vitamin A was given orally.

Primary Outcome Measures

Name	Time	Method
Total traced vitamin A mass	Baseline through 152 days	Total amount of endogenous vitamin A determined by mathematical model, (µmol).

Secondary Outcome Measures

Name	Time	Method
Compartmental model fractional transfer coefficients	Baseline through 152 days	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).
Vitamin A disposal rate	Baseline through 152 days	Daily loss or utilization of vitamin A, (µmol/d).
Vitamin A tracer partitioning	Baseline through 152 days	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).
Compartmental model complexity	Baseline through 152 days	Required number of compartments in mathematical model needed to adequately fit data.
Vitamin A equilibration time and partitioning	Baseline through 152 days	Time taken for vitamin A to equilibrate with body stores, (d).
Vitamin A dietary intake	Baseline	Vitamin A dietary intake by food frequency questionnaire, (µg retinol activity equivalents/d).
Serum vitamin A half-life	Baseline through 152 days	Half-life of vitamin A in serum, (d).

Trial Locations

Locations (1)

Department of Nutritional Sciences, University of Wisconsin-Madison; 🇺🇸 Madison, Wisconsin, United States