ClinicalTrials.Veeva

Menu

Trial of Vitamin D Supplements to Raise Calcidiol Levels of Pregnant Women in Mongolia

Mass General Brigham logo

Mass General Brigham

Status

Completed

Conditions

Vitamin D Deficiency
Pregnancy

Treatments

Dietary Supplement: 4000 IU Vitamin D3 in prenatal vitamin
Dietary Supplement: 2000 IU Vitamin D3 in prenatal vitamin
Dietary Supplement: 600 IU Vitamin D3 in prenatal vitamin

Study type

Interventional

Funder types

Other

Identifiers

NCT02395081
14-0591-02

Details and patient eligibility

About

A double-blind randomized, placebo-controlled trial comparing the impact of 600 IU, 2000 IU, or 4000 IU of Vitamin D3 on third trimester 25(OH)D levels and change from baseline. The Vitamin D will be integrated in a standard prenatal vitamin, which will be taken from 12-16 weeks' gestation and continue throughout pregnancy. Umbilical cord 25(OH)D levels will also be determined. The investigators will generate preliminary data regarding Vitamin D intake and hypertensive disorders, blood pressure, and arterial function measured by tonography. The investigators will independently test blood pressure and proteinuria to identify preeclampsia cases.

Full description

Vitamin D deficiency (serum 25(OH)D levels <20 ng/ml or 50 nmol/l) is widespread among Mongolians and is nearly universal during the winter months. The investigators have conducted a series of studies which have shown nearly universal Vitamin D deficiency in the winter months.

Observational studies in the U.S. have linked low 25(OH)D levels in women to a higher risk of preeclampsia. Mongolians also report levels of preeclampsia that are 3 times higher than those in the U.S (official reports cite 15%, though this may include gestational hypertension).

Given the widespread Vitamin D deficiency in Mongolian women, the high prevalence of hypertensive pregnancy in Mongolia, and the observational studies linking low 25(OH)D levels with preeclampsia risk, the investigators are conducting a pilot Vitamin D dosing trial to:

  • Determine what level of Vitamin D supplementation is needed to secure 25(OH)D levels of at least 20 ng/ml in pregnant Mongolian women
  • Generate preliminary data in support of a funding application for a larger trial of Vitamin D supplements to prevent preeclampsia in Mongolia

A double-blind randomized, placebo-controlled trial comparing the impact of 600 IU, 2000 IU, or 4000 IU of Vitamin D3 on third trimester 25(OH)D levels and change from baseline. The Vitamin D will be integrated in a standard prenatal vitamin, which will be taken from 12-16 weeks' gestation and continue throughout pregnancy. Umbilical cord 25(OH)D levels will also be determined. The investigators will generate preliminary data regarding Vitamin D intake and hypertensive disorders, blood pressure, and arterial function measured by tonography. The investigators will independently test blood pressure and proteinuria to identify preeclampsia cases.

The investigators will enroll 360 women who plan to receive their prenatal care and deliver at Zuun Kharaa Hospital in the Selenge province in northern Mongolia. Enrollment will be stratified by season. 120 women will be randomized to each of the three doses of vitamin D (600, 2000, 4000 IU) included in a standard prenatal vitamin.

Calcemia will be monitored two months after randomization and weeks 36-40 of pregnancy. Adverse events of pregnancy will be reported to the Data Safety and Monitoring Board (DSMB) and Institutional Review Board (IRB) per protocol.

Data will be gathered by a Mongolian study coordinator and local clinicians. A DSMB comprised of a U.S. and Mongolian clinicians and statisticians will monitor study data for safety.

Enrollment

360 patients

Sex

Female

Ages

18+ years old

Volunteers

Accepts Healthy Volunteers

Inclusion criteria

  • Age 18 or older
  • 12-16 weeks pregnant
  • Receiving prenatal care at Zuun Kharaa Hospital and planning to deliver at Zuun Kharaa Hospital
  • Willing not to take any additional vitamin D supplements, other than the study dispensed pills

Exclusion criteria

  • Existing known seizure disorder, renal failure, parathyroid disease, thyroid disease, sarcoidosis, cancer, or tuberculosis. (Tuberculosis is routinely screened in pregnancy)
  • History of kidney stones
  • Known sensitivity to multivitamin preparations
  • Taking vitamin D supplements containing >600 IU/day.

Trial design

Primary purpose

Prevention

Allocation

Randomized

Interventional model

Parallel Assignment

Masking

Quadruple Blind

360 participants in 3 patient groups, including a placebo group

600 IU
Placebo Comparator group
Description:
Women will receive prenatal vitamins containing 600 IU of Vitamin D.
Treatment:
Dietary Supplement: 600 IU Vitamin D3 in prenatal vitamin
2000 IU
Experimental group
Description:
Women will receive prenatal vitamins containing 2000 IU of Vitamin D.
Treatment:
Dietary Supplement: 2000 IU Vitamin D3 in prenatal vitamin
4000 IU
Experimental group
Description:
Women will receive prenatal vitamins containing 4000 IU of Vitamin D.
Treatment:
Dietary Supplement: 4000 IU Vitamin D3 in prenatal vitamin

Trial contacts and locations

1

Loading...

Data sourced from clinicaltrials.gov

Clinical trials

Find clinical trialsTrials by location
© Copyright 2026 Veeva Systems