Vitamin D Dynamics in Women

Sponsor

Cornell University (Other)

Overall Status

Completed

CT.gov ID

NCT02705287

Collaborator

University of Rochester (Other)

Enrollment

Location

Duration (Months)

0.4

Patients Per Site Per Month

Study Details

Study Description

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.

Condition or Disease	Intervention/Treatment	Phase
Pregnancy	Other: Vitamin D dynamics-pregnant Other: Vitamin D dynamics-nonpregnant Other: Delivery-placental transfer Other: Delivery-Vitamin D Other: Delivery-25(OH) Vitamin D

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:

Obtain pilot data on the absorption of vitamin D3 in non-pregnant and pregnant women, following oral dosing with deuterated vitamin D3
Obtain pilot data on the dynamics of the conversion of vitamin D3 into 25-hydroxyvitamin D3, following dosing with oral deuterated vitamin D3
Estimate the serum half-life of vitamin D3 and 25-hydroxyvitamin D3 in non-pregnant and pregnant women
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
Evaluate the ability of the placenta to rapidly transfer maternally absorbed vitamin D3 to the fetus at term
Evaluate the ability of the placenta to rapidly transfer maternally absorbed 25(OH)D3 to the fetus at term

Study Design

Study Type:

Observational

Actual Enrollment :

18 participants

Observational Model:

Case-Control

Time Perspective:

Prospective

Official Title:

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

Study Start Date :

Jul 1, 2015

Actual Primary Completion Date :

Jul 1, 2019

Actual Study Completion Date :

Jul 1, 2019

Arms and Interventions

Arm	Intervention/Treatment
Vitamin D dynamics-pregnant Pregnant women recruited to measure Vitamin D dynamics during pregnancy.	Other: Vitamin D dynamics-pregnant tracer dose of deuterated vitamin D3
Vitamin D dynamics-nonpregnant Non-pregnant women recruited to measure Vitamin D dynamics.	Other: Vitamin D dynamics-nonpregnant tracer dose of deuterated vitamin D3
Delivery-placental transfer Pregnant women planning to deliver by scheduled c-section who will be dosed with vitamin D3 in late gestation (week 36-38).	Other: Delivery-placental transfer tracer dose of deuterated vitamin D3 to women in late gestation
Delivery-Vitamin D 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	Other: Delivery-Vitamin D 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
Delivery-25(OH) Vitamin D Pregnant women will be dosed with 25(OH)D3 when they come in for their pre-surgical appointments	Other: Delivery-25(OH) Vitamin D women will be dosed with deuterated 25(OH)D3 when they come in for their pre-surgical appointments

Outcome Measures

Primary Outcome Measures

Serum vitamin D3 half-life [Across 30 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 25 μg (1000 IU) of [6,19,19-d3]-vitamin D3 has been added. Women will return to the on Day 2, 8, 12, 16, 20 and 30 (± 2 days) for an additional blood sample (10 mL each) to assess the disappearance of the deuterated D3.
Forms of vitamin D can be transferred across the placenta [Across 1-2 days study period]
At delivery a sample of cord blood and placental tissue will be obtained to evaluate the presence of labeled vitamin D or its metabolites in the neonate at birth and in the placental tissue

Secondary Outcome Measures

Serum 25-hydroxyvitamin D3 half-life [Across 30 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 25 μg (1000 IU) of [6,19,19-d3]-vitamin D3 has been added. Women will return to the on Day 2, 8, 12, 16, 20 and 30 (± 2 days) for an additional blood sample (10 mL each) to examine the appearance and subsequent disappearance of deuterated 25(OH)D3.

Eligibility Criteria

Criteria

Ages Eligible for Study:

19 Years to 35 Years

Sexes Eligible for Study:

Female

Accepts Healthy Volunteers:

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)