Vitamin D Dynamics in Women

Vitamin D Dynamics in Pregnant Women and Non-Pregnant Women of Reproductive Age

Sponsors

Lead Sponsor: Cornell University

Collaborator: University of Rochester

Source Cornell University
Brief Summary

The goal of this pilot 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 calcitropic hormone status at this key life stage. At the conclusion of this study, the investigators will have obtained novel information on the absorption and utilization of vitamin D in women and determined if maternal vitamin D3 or maternal 25(OH)D3, or both, can be transferred across the placenta to the fetus. 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. Obtain pilot data on the absorption of vitamin D3 in non-pregnant and pregnant women, following oral dosing with deuterated vitamin D3

2. Obtain pilot data on the dynamics of the conversion of vitamin D3 into 25-hydroxyvitamin D3, following dosing with oral deuterated vitamin D3

3. Estimate the serum half-life of vitamin D3 and 25-hydroxyvitamin D3 in non-pregnant and pregnant women

4. Evaluate the absorption of vitamin D3 in late gestation and evaluate the concentrations of these forms of vitamin D in the cord blood at birth

5. Evaluate the ability of the placenta to rapidly transfer maternally absorbed vitamin D3 to the fetus at term

6. Evaluate the ability of the placenta to rapidly transfer maternally absorbed 25(OH)D3 to the fetus at term

Overall Status Completed
Start Date July 2015
Completion Date July 2019
Primary Completion Date July 2019
Study Type Observational
Primary Outcome
Measure Time Frame
Serum vitamin D3 half-life Across 30 days study period
Forms of vitamin D can be transferred across the placenta Across 1-2 days study period
Secondary Outcome
Measure Time Frame
Serum 25-hydroxyvitamin D3 half-life Across 30 days study period
Enrollment 18
Condition
Intervention

Intervention Type: Other

Intervention Name: Vitamin D dynamics-pregnant

Description: tracer dose of deuterated vitamin D3

Arm Group Label: Vitamin D dynamics-pregnant

Intervention Type: Other

Intervention Name: Vitamin D dynamics-nonpregnant

Description: tracer dose of deuterated vitamin D3

Arm Group Label: Vitamin D dynamics-nonpregnant

Intervention Type: Other

Intervention Name: Delivery-placental transfer

Description: tracer dose of deuterated vitamin D3 to women in late gestation

Arm Group Label: Delivery-placental transfer

Intervention Type: Other

Intervention Name: Delivery-Vitamin D

Description: women will be dosed with deuterated vitamin D3 at term when they come in for their pre-surgical appointments prior to their scheduled c-section

Arm Group Label: Delivery-Vitamin D

Intervention Type: Other

Intervention Name: Delivery-25(OH) Vitamin D

Description: women will be dosed with deuterated 25(OH)D3 when they come in for their pre-surgical appointments

Arm Group Label: Delivery-25(OH) Vitamin D

Eligibility

Sampling Method: Non-Probability Sample

Criteria:

Inclusion Criteria (Non-pregnant and pregnant participants participants):

- Caucasian race

- Age 19-35

- Body mass index (BMI) or pre-pregnancy BMI (If currently pregnant) < 28 kg/m2

Inclusion Criteria (Additional criteria for pregnant participants):

- Singleton pregnancy

- 20 to <36 weeks pregnant during study participation

- No pregnancy complications

- Planning to delivery by scheduled c-section (if participating in the placental transfer study Aims 4-6)

Exclusion Criteria (Non-pregnant and pregnant participants):

- BMI or pre-pregnancy BMI ≥ 28 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

Gender: Female

Minimum Age: 19 Years

Maximum Age: 35 Years

Healthy Volunteers: No

Overall Official
Location
Facility: University of Rochester, 518 Hylan Building
Location Countries

United States

Verification Date

February 2020

Responsible Party

Type: Sponsor

Keywords
Has Expanded Access No
Arm Group

Label: Vitamin D dynamics-pregnant

Description: Pregnant women recruited to measure Vitamin D dynamics during pregnancy.

Label: Vitamin D dynamics-nonpregnant

Description: Non-pregnant women recruited to measure Vitamin D dynamics.

Label: Delivery-placental transfer

Description: Pregnant women planning to deliver by scheduled c-section who will be dosed with vitamin D3 in late gestation (week 36-38).

Label: Delivery-Vitamin D

Description: Pregnant women will be dosed with vitamin D3 at term when they come in for their pre-surgical appointments prior to their scheduled c-section

Label: Delivery-25(OH) Vitamin D

Description: Pregnant women will be dosed with 25(OH)D3 when they come in for their pre-surgical appointments

Patient Data No
Study Design Info

Observational Model: Case-Control

Time Perspective: Prospective

Source: ClinicalTrials.gov