Vitamin D Dynamics in Women

NCT ID: NCT02705287

Last Updated: 2025-02-27

Basic Information

• Recruitment Status: RECRUITING
• Total Enrollment: 160 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2024-10-28
• Study Completion Date: 2029-05-31

Brief 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. 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.

Conditions

Pregnancy

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Vitamin D dynamics- pregnant

Pregnant women recruited to measure Vitamin D dynamics during pregnancy.

Vitamin D dynamics-pregnant

Intervention Type: OTHER

tracer dose of deuterated vitamin D3

Vitamin D dynamics-nonpregnant

Non-pregnant women recruited to measure Vitamin D dynamics.

Vitamin D dynamics-nonpregnant

Intervention Type: OTHER

tracer dose of deuterated vitamin D3

Interventions

Vitamin D dynamics-pregnant

tracer dose of deuterated vitamin D3

Intervention Type: OTHER

Vitamin D dynamics-nonpregnant

tracer dose of deuterated vitamin D3

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• 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

• Singleton pregnancy
• Recruited in first trimester, second trimester, or third trimester
• No pregnancy complications

Exclusion Criteria

• 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)

• Gestational diabetes
• Pregnancy hypertension

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 39 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

University of Rochester

OTHER

Sponsor Role: collaborator

Cornell University

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Kimberly O. O'Brien, PhD

Role: PRINCIPAL_INVESTIGATOR

Cornell University

Eva Pressman, MD

Role: PRINCIPAL_INVESTIGATOR

University of Rochester

Locations

University of Rochester, 518 Hylan Building

Rochester, New York, United States

Site Status: RECRUITING

Countries

United States

Central Contacts

Kimberly O. O'Brien, PhD

Role: CONTACT

koo4@cornell.edu

607-255-3743

Facility Contacts

Brenda Kavanaugh

Role: primary

bkavanaugh@orpa.rochester.edu

585-275-1504

Other Identifiers

RSRB00057617

Identifier Type: OTHER

Identifier Source: secondary_id

IRB # 1509005821

Identifier Type: -

Identifier Source: org_study_id