Recruiting

Vitamin D

Sponsor:

Cornell University

Code:

NCT02705287

Conditions

Pregnancy

Eligibility Criteria

Sex: Female

Age: 20 - 39

Healthy Volunteers: Not accepted

Interventions

Vitamin D dynamics-pregnant

Vitamin D dynamics-nonpregnant

Study Details

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.

Conditions

Pregnancy

Study ID

NCT02705287

Start date

Oct 28, 2024

Status verified date

Mar, 2026

Completion date

May, 2029

Anticipated

Primary completion date

May, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 20 - 39

Healthy Volunteers: Not accepted

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

Study Design

Enrollment

160 participants

Anticipated

Interventions and Outcome Measures

Arms

Vitamin D dynamics- pregnant

Pregnant women recruited to measure Vitamin D dynamics during pregnancy.

Vitamin D dynamics-nonpregnant

Non-pregnant women recruited to measure Vitamin D dynamics.

Interventions

Vitamin D dynamics-pregnant

tracer dose of deuterated vitamin D3

Vitamin D dynamics-nonpregnant

tracer dose of deuterated vitamin D3

Primary outcome measure

  • 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 ]

Central Contacts and Locations

Central contacts

Kimberly O. O'Brien, PhD

607-255-3743koo4@cornell.edu

Locations

University of Rochester, 518 Hylan Building

Recruiting

Rochester, New York, United States, 14627

Contacts

Brenda Kavanaugh

585-275-1504bkavanaugh@orpa.rochester.edu

More Information

Sponsor

Cornell University

Last update posted

Apr 1, 2026

Last verified

Mar, 2026

Keywords

  • vitamin D
  • half life
  • kinetics

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Cornell University on 2026-04-01.