PregnancyNCT02705287
Vitamin D Dynamics in Women
An observational study of Pregnancy, run by Cornell University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 20 to 39 years, women only
- Conditions the study is for
- Pregnancy
- What is being tested?
- Vitamin D dynamics-pregnant and Vitamin D dynamics-nonpregnant
- How many people
- 160 participants
- Where
- 1 siteUnited States
- Study dates
- 28 Oct 2024to May 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 39 years
- Women only
- No healthy volunteers
- Adult
Study population: Pregnant women and non-pregnant women of reproductive age
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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Rochester, 518 Hylan Building
Rochester, New York, 14627
Brenda Kavanaugh, 585-275-1504, bkavanaugh@orpa.rochester.edu
About this study
Official title: Vitamin D Dynamics in Pregnant Women and Non-Pregnant Women of Reproductive Age
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.
Read the 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:
- 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.
- 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.
- 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.
- Conditions
- Pregnancy
- Being tested
- Vitamin D dynamics-pregnant, Vitamin D dynamics-nonpregnant
- Keywords
- vitamin D, half life, kinetics
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Vitamin D dynamics-pregnantOther
tracer dose of deuterated vitamin D3
Vitamin D dynamics-nonpregnantOther
tracer dose of deuterated vitamin D3
| Study group | Role | What they receive |
|---|---|---|
| Vitamin D dynamics- pregnant | Pregnant women recruited to measure Vitamin D dynamics during pregnancy. Receives: Other: Vitamin D dynamics-pregnant | |
| Vitamin D dynamics-nonpregnant | Non-pregnant women recruited to measure Vitamin D dynamics. Receives: Other: Vitamin D dynamics-nonpregnant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Impact of pregnancy on serum vitamin D absorption
A baseline blood sample (20 mL) will be obtained for analysis of the baseline concentrations of indicators of vitamin D status. Each woman will be asked to ingest two pieces of toast onto which a dose of 35 μg of [6,19,19-d3]-vitamin D3 has been added. Women will return to the at 4 hour, 8 hour, Day 2, 10, 25, and 40 (± 2 days) for an additional blood sample (15 mL each) to assess the disappearance of the tri-deuterated D3, conversion into 25(OH)D3, and serum half-life of 25(OH)D3.
Measured: Across 40 days study period
Impact of obesity on vitamin D absorption
A baseline blood sample (20 mL) will be obtained for analysis of the baseline concentrations of indicators of vitamin D status. Each woman will be asked to ingest two pieces of toast onto which a dose of 35 μg of [6,19,19-d3]-vitamin D3 has been added. Women will return to the at 4 hour, 8 hour, Day 2, 10, 25, and 40 (± 2 days) for an additional blood sample (15 mL each) to assess the disappearance of the tri-deuterated D3, conversion into 25(OH)D3, and serum half-life of 25(OH)D3. Body composition measure using Bioelectrical Impedance Analysis (BIA) will be conducted on Day 0 for all participants and Day 40 for he pregnant participants to obtain information on BMI and fat mass. Adipose tissue (<1 gram) will be extracted using needle biopsy from the upper buttock area on all participants for D content analysis.
Measured: Across 40 days study period
Impact of ancestry on serum vitamin D absorption
A baseline blood sample (20 mL) will be obtained for analysis of the baseline concentrations of calcitropic hormones and indicators of vitamin D status. Each woman will be asked to ingest one quarter piece of toast onto which a dose of 35 ug of [6,19,19-d3]-vitamin D3 has been added. Women will return to the at 4 hour, 8 hour, Day 1, 3, 10, 25, and 40 (± 2 days) for an additional blood sample (15 mL each) to assess the disappearance of the tri-deuterated D3, conversion into 25(OH)D3, and serum half-life of 25(OH)D3. DNA will be extracted to perform ancestry genotyping and determine vitamin D binding protein genotypes.
Measured: Across 40 days study period
Secondary outcomes (1)
Placental protein quantification
At delivery placental tissue will be collected for evaluation of placental mRNA expression and protein abundance of CYP2R1, CYP24A1 and CYP27B1 following methods we, and others have published. This will help us obtain data on placental contributions to D utilization to inform our mathematical model and hypotheses.
Measured: Across 40 days study period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Mar 2016 (estimated)
- Study start28 Oct 2024
- Primary completionMay 2028 (estimated)
- Study completionMay 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for PregnancyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 160 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cornell University
- Sponsor type
- University, hospital or other
- Collaborators
- University of Rochester
- Responsible party
- Sponsor
- Investigators
- Kimberly O. O'Brien, PhD, Principal investigator, Cornell UniversityEva Pressman, MD, Principal investigator, University of Rochester
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02705287
- Sponsor's protocol ID
- IRB # 1509005821
- Other IDs
- RSRB00057617
- Status last verified
- Mar 2026
- First submitted
- 7 Mar 2016
- Last updated
- 1 Apr 2026
- Results posted
- No
- Data monitoring committee
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vitamin D Dynamics in Pregnant Women and Non-Pregnant Women of Reproductive Age
- ClinicalTrials.gov ID
- NCT02705287
- Acronym / sponsor ID
- IRB # 1509005821
- Conditions
- Pregnancy
- Keywords
- vitamin D, half life, kinetics
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 160 participants (estimated)
- Lead sponsor
- Cornell UniversityUniversity, hospital or other
- Collaborators
- University of Rochester
- Study start
- 28 Oct 2024 (actual)
- Primary completion
- May 2028 (estimated)
- Study completion
- May 2029 (estimated)
- First posted
- 10 Mar 2016 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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:
- 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.
- 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.
- 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.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Vitamin D dynamics- pregnant | – | Other: Vitamin D dynamics-pregnantPregnant women recruited to measure Vitamin D dynamics during pregnancy. |
| Vitamin D dynamics-nonpregnant | – | Other: Vitamin D dynamics-nonpregnantNon-pregnant women recruited to measure Vitamin D dynamics. |
Who may qualify
- Ages
- 20 to 39 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Pregnant women and non-pregnant women of reproductive age
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Vitamin D dynamics-pregnanttracer dose of deuterated vitamin D3 | Other | Vitamin D dynamics- pregnant |
| Vitamin D dynamics-nonpregnanttracer dose of deuterated vitamin D3 | Other | Vitamin D dynamics-nonpregnant |
Primary outcome
Impact of pregnancy on serum vitamin D absorption
Time frame: Across 40 days study period
A baseline blood sample (20 mL) will be obtained for analysis of the baseline concentrations of indicators of vitamin D status. Each woman will be asked to ingest two pieces of toast onto which a dose of 35 μg of [6,19,19-d3]-vitamin D3 has been added. Women will return to the at 4 hour, 8 hour, Day 2, 10, 25, and 40 (± 2 days) for an additional blood sample (15 mL each) to assess the disappearance of the tri-deuterated D3, conversion into 25(OH)D3, and serum half-life of 25(OH)D3.
Impact of obesity on vitamin D absorption
Time frame: Across 40 days study period
A baseline blood sample (20 mL) will be obtained for analysis of the baseline concentrations of indicators of vitamin D status. Each woman will be asked to ingest two pieces of toast onto which a dose of 35 μg of [6,19,19-d3]-vitamin D3 has been added. Women will return to the at 4 hour, 8 hour, Day 2, 10, 25, and 40 (± 2 days) for an additional blood sample (15 mL each) to assess the disappearance of the tri-deuterated D3, conversion into 25(OH)D3, and serum half-life of 25(OH)D3. Body composition measure using Bioelectrical Impedance Analysis (BIA) will be conducted on Day 0 for all participants and Day 40 for he pregnant participants to obtain information on BMI and fat mass. Adipose tissue (<1 gram) will be extracted using needle biopsy from the upper buttock area on all participants for D content analysis.
Impact of ancestry on serum vitamin D absorption
Time frame: Across 40 days study period
A baseline blood sample (20 mL) will be obtained for analysis of the baseline concentrations of calcitropic hormones and indicators of vitamin D status. Each woman will be asked to ingest one quarter piece of toast onto which a dose of 35 ug of [6,19,19-d3]-vitamin D3 has been added. Women will return to the at 4 hour, 8 hour, Day 1, 3, 10, 25, and 40 (± 2 days) for an additional blood sample (15 mL each) to assess the disappearance of the tri-deuterated D3, conversion into 25(OH)D3, and serum half-life of 25(OH)D3. DNA will be extracted to perform ancestry genotyping and determine vitamin D binding protein genotypes.
1 secondary outcome
Placental protein quantification
Time frame: Across 40 days study period
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Apr 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Kimberly O. O'Brien, PhD principal investigator
Cornell University
Eva Pressman, MD principal investigator
University of Rochester
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Pregnancy, run by Cornell University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 1 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Kimberly O. O'Brien, PhD (607-255-3743, koo4@cornell.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Impact of pregnancy on serum vitamin D absorption (time frame: Across 40 days study period). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Apr 2026.