Evaluation of Vitamin D Requirements During Pregnancy

Medical University of South Carolina (MUSC)

Status and phase: Completed; Phase 3

Conditions: Vitamin D Deficiency

Treatments: Drug: cholecalciferol; Drug: cholecalciferol (vitamin D3)

Study type: Interventional

Funder types: Other; NIH

Identifiers

NCT00292591

5R01HD043921 (U.S. NIH Grant/Contract)

R01HD043921

Details and patient eligibility

About

The purpose of this study is to determine the effectiveness of vitamin D supplementation during pregnancy starting at the beginning of the second trimester. Mothers will be randomized to one of three vitamin D dosing groups: 400, 2,000 or 4,000 international units per day. It is hypothesized that the highest dosing regimen will result in a better vitamin D status of women regardless of their ethnicity or race.

Full description

The prevalence of hypovitaminosis D in reproductive aged African-American women occurs at a rate of > 40%. Two factors have contributed to this public health problem: an inadequate DRI for vitamin D and avoidance of sun exposure/use of sunscreen. This startling rate of hypovitaminosis D requires that the DRI for vitamin D in pregnancy be evaluated in a detailed manner. The Cochrane Library (2002) released a report stating that there is insufficient data to evaluate the effects of vitamin D supplementation during pregnancy. Recently, the safety of prolonged supplementation with up to 25x's DRI (10,000 IU/day) was demonstrated in nonpregnant adults. It is essential to determine what dose of vitamin D is required to eliminate hypovitaminosis D during pregnancy and provide the fetus/neonate with adequate vitamin D stores during development and growth, particularly in darkly pigmented individuals. The aim of this research proposal, then, is to determine the efficacy, effectiveness, and safety of maternal vitamin D supplementation (as a function of ethnicity and UV exposure) in the prevention of hypovitaminosis D in the pregnant mother and her fetus/neonate. We hypothesize that darkly pigmented mothers will require substantially higher oral supplementation with vitamin D to eliminate hypovitaminosis D as compared to their Caucasian counterparts. We propose a comprehensive clinical trial to test our hypothesis. Mothers at 12 weeks' gestation will be randomized to one of three vitamin D treatment groups:

1. Control, 400-,
2. 2,000-, or
3. 4,000 IU/day to be continued throughout pregnancy.

Calcium and vitamin D homeostasis and skeletal remodeling in the mother will be monitored closely throughout the pregnancy. Bone density of the mother will be measured at 12 weeks' gestation and one-month postpartum. Follow-up growth and skeletal integrity assessments of the infant will be performed at birth, 1, 6 and 12 months stratified by infant feeding regime. Through these proposed studies, the prevalence of hypovitaminosis D among mothers, their developing fetuses and neonates, and the utility of maternal therapeutic intervention with vitamin D for both mother and fetus/infant will be assessed.

Enrollment: 501 patients

Sex: Female

Ages: 16 to 45 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

1. Women who are within the ages of 16-45 years
2. In good general health
3. Less than 12 weeks pregnant (based on last menstrual period)

Exclusion criteria

1. Mothers with preexisting type I or type II diabetes
2. Mothers with preexisting hypertension
3. Mothers with preexisting parathyroid disease or uncontrolled thyroid disease
4. Mothers with multiple fetuses (e.g., twins, triplets, etc.)

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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501 participants in 3 patient groups

cholecalciferol-400 IU

Active Comparator group

Description:

Control group receiving 400 IU/day plus 0 IU vitamin D3 as placebo/day

Treatment:

Drug: cholecalciferol

Drug: cholecalciferol (vitamin D3)

cholecalciferol 2000 IU

Experimental group

Description:

Experimental group receiving 2000 IU total vitamin D3/day.

Treatment:

Drug: cholecalciferol

Drug: cholecalciferol (vitamin D3)

cholecalciferol 4000 IU

Experimental group

Description:

Experimental group receiving 4000 IU/day cholecalciferol

Treatment:

Drug: cholecalciferol

Drug: cholecalciferol (vitamin D3)