Vitamin D Dynamics in Women
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Vitamin D dynamics-pregnant, Vitamin D dynamics-nonpregnant.
- Who it may be relevant to
- Registry conditions: Pregnancy. Basic parameters: 20 years — 39 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- United States
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
Unsure about the terms? Read our patient guide →
Official title
Vitamin D Dynamics in Pregnant Women and Non-Pregnant Women of Reproductive Age
Overview
The goal of this project is to utilize stable isotopically labeled vitamin D3 and state of the art mass spectrometric methodology to assess vitamin D dynamics during pregnancy in relation to relation to obesity and vitamin D binding protein genotype. At the conclusion of this study, the investigators will have obtained novel information on the absorption and utilization of vitamin D in women and the degree to which vitamin D utilization during pregnancy is impacted by genetic ancestry, vitamin D binding protein concentration and genotype and by excess adiposity. The long-term goal is to better understand the unique metabolism of vitamin D during pregnancy.
Detailed description
Nearly 30% of US women are either vitamin D insufficient or deficient. Vitamin D inadequacy during gestation is increasingly linked to adverse birth outcomes including preterm birth, the risk of cesarean section and placental and pregnancy-associated infections. At this time the Institute of Medicine (IOM) has not advocated any increase in vitamin D intake across gestation but this remains controversial in large part due to insufficient information on the basic physiology of vitamin D. Pregnancy induces dramatic changes in regulation of vitamin D. The investigators hypothesize that increased maternal, placental, and fetal vitamin D requirements during late gestation will result in an increase in vitamin D absorption and a decrease in the half-life of both vitamin D3 and 25-hydroxyvitamin D. The fetus is entirely dependent on maternal vitamin D to meet its requirements for this nutrient. Maternal vitamin D is thought to be passively transferred across the placenta to the fetus given that neonatal concentrations of 25(OH)D are at least 20-30% lower than maternal 25(OH)D concentrations. To date, much of what is known about vitamin D absorption and utilization in humans has been extrapolated from early radiotracer studies in adult men and non-pregnant women and there are no in vivo data to determine if maternal vitamin D3 or maternal 25(OH)D3, or both, can be transferred across the placenta to the fetus
The specific aims of this project are to:
1. To characterize the impact of pregnancy on the absorption of vitamin D3, conversion into 25(OH)D3, and serum half-life of 25OH)D3 in pregnant and non-pregnant women using tri-deuterated vitamin D3, state of the art UHPLC-MS/MS methodology and mathematical modeling. 2. To study the impact of obesity on vitamin D kinetics and the D content of serum and adipose tissue in pregnant and non-pregnant women. 3. To evaluate the impact of genetic ancestry on vitamin D kinetics and the D content of serum and adipose tissue in pregnant and non-pregnant women.
Interventions
- Other Vitamin D dynamics-pregnant
tracer dose of deuterated vitamin D3 - Other Vitamin D dynamics-nonpregnant
tracer dose of deuterated vitamin D3
Primary outcome measures
- Impact of pregnancy on serum vitamin D absorption [Time frame: Across 40 days study period]
- Impact of obesity on vitamin D absorption [Time frame: Across 40 days study period]
- Impact of ancestry on serum vitamin D absorption [Time frame: Across 40 days study period]
Secondary outcome measures (1)
- Placental protein quantification [Time frame: Across 40 days study period]
Eligibility criteria
Inclusion Criteria (Non-pregnant and pregnant participants participants):
- Self-reported White and Black women
- Age 20-39
- Body mass index (BMI) 1or pre-pregnancy BMI (If currently pregnant) either 18.5-24.9 kg/m2 or greater than or equal to 30 kg/m2
Inclusion Criteria (Additional criteria for pregnant participants):
- Singleton pregnancy
- Recruited in first trimester, second trimester, or third trimester
- No pregnancy complications
Exclusion Criteria (Non-pregnant and pregnant participants):
- BMI or pre-pregnancy BMI <18.5 kg/m2
- Human immunodeficiency virus (HIV) infection
- Diagnosed eating disorder
- Malabsorption disease
- Diabetes
- Elevated diastolic blood pressure (>110 mm/Hg)
- Steroid use
- Substance abuse history
- Current use of medications known to influence vitamin D or calcium homeostasis
- Plans to travel to lower latitude during the 20-day study period
- Plans to become pregnant during the study period (non-pregnant only)
- Refuses to discontinue tanning bed use during study period
- Refuses to discontinue vitamin or mineral supplement use during study period (non-pregnant only)
Exclusion Criteria (Additional criteria for pregnant participants):
- Gestational diabetes
- Pregnancy hypertension
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Observational model
- Cohort
Study locations
United States · 1 center
- University of Rochester, 518 Hylan Building — Rochester
Identifiers
NCT: NCT02705287 · IRB # 1509005821 · RSRB00057617