Vitamin A Kinetics
Conditions
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.
Interventions
OTHERVitamin A tracer
A stable isotope tracer of vitamin A was given orally.
Sponsors
University of Wisconsin, Madison
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
19 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Total traced vitamin A mass | Baseline through 152 days | Total amount of endogenous vitamin A determined by mathematical model, (µmol). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Compartmental model complexity | Baseline through 152 days | Required number of compartments in mathematical model needed to adequately fit data. |
| 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). |
| Serum vitamin A half-life | Baseline through 152 days | Half-life of vitamin A in serum, (d). |
| Vitamin A equilibration time and partitioning | Baseline through 152 days | Time taken for vitamin A to equilibrate with body stores, (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). |
| Vitamin A dietary intake | Baseline | Vitamin A dietary intake by food frequency questionnaire, (µg retinol activity equivalents/d). |
| Vitamin A disposal rate | Baseline through 152 days | Daily loss or utilization of vitamin A, (µmol/d). |
Countries
United States
Outcome results
None listed