Effects of Vitamin D Supplementation During Pregnancy on Clinical Outcomes and Immune Function

Study Overview
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Brief Summary
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Researchers at the USDA Western Human Nutrition Research Center and clinicians at UC Davis Medical Center are currently conducting a study on the effects of vitamin D supplementation during pregnancy on maternal health and immune function. The investigators believe that vitamin D supplementation at levels greater than the current recommendation is beneficial for maternal health during pregnancy. In particular, there is evidence that vitamin D deficiency during pregnancy puts women at greater risk for diseases like pre-eclampsia, which may be due to an imbalance in immune function at the placenta. This randomized, double-blind study is designed to test this hypothesis. Pregnant women who participate in the study receive either 400 IU or 2,000 IU of vitamin D per day for the duration of their pregnancy. The investigators will collect blood at three time points during pregnancy (16-20 weeks, 26-28 weeks, 36 weeks gestation) for analysis of immune function and vitamin D status. The investigators are also collecting data on clinical parameters, such as blood pressure and glucose tolerance.

Official Title
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Assessment of Inflammatory Markers and Pregnancy Outcomes in Vitamin D-Supplemented Women at Risk of Vitamin D Deficiency: A Double-Blind, Randomized Controlled Trial

Conditions
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Vitamin D Deficiency

Intervention / Treatment
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* Dietary Supplement: 400 IU vitamin D3
* Dietary Supplement: 2,000 IU Vitamin D3


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women Less than 20 weeks gestation Over 18 years of age Able to swallow nutritional supplements Exclusion Criteria: Use of medications known to affect vitamin D metabolism Diagnosis of type 1 diabetes History of thyroid, renal, or liver disease Problems with digestion or absorption

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: 400 IU Vitamin D3<br>Women in this study arm receive 400 IU of vitamin D3 per day, or what is in a standard prenatal multivitamin. They also receive a placebo study supplement. | Dietary Supplement: 400 IU vitamin D3<br>* Women in this study arm receive 400 IU of vitamin D3 per day, or what is in a standard prenatal multivitamin. They also receive a placebo study supplement.<br>|
| Experimental: 2,000 IU Vitamin D3<br>Women in this arm receive 2,000 IU vitamin D per day: 400 IU from a standard prenatal multivitamin plus an additional 1,600 IU vitamin D3 in the study supplement. | Dietary Supplement: 2,000 IU Vitamin D3<br>* Women in this arm receive 2,000 IU vitamin D per day: 400 IU from a standard prenatal multivitamin plus an additional 1,600 IU vitamin D3 in the study supplement.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in T-cell cytokine expression | Inflammatory and regulatory cytokines will be measured in cultured T-cells by flow cytometry. | 16-20 wks, 26-28 wks, and 36 wks gestation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Vitamin D status | Serum 25-OH vitamin D and 1, 25 (OH)2 Vitamin D | 16-20 wks, 26-28 wks, 36 wks gestation | 
| Change in innate immune function | Monocyte and NK cell cytokine expression and response to stimulation with Toll-like Receptor agonists. | 16-20 wks, 26-28 wks, 36 wks gestation | 
| Change in blood pressure | Blood pressure will be measured using standard techniques. | 16-20 wks, 26-28 wks, 36 wks gestation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pregnancy, immune function