Vitamin D Supplementation for the Prevention of GDM

Study Overview
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Brief Summary
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This study was a double-blind multicenter randomized controlled study.

Detailed Description
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This study intends to adopt a randomized controlled study design, and randomly divide pregnant women at high risk of GDM into intervention group (VitD3:1600 IU/ day) (n=800) and control group (placebo:2 tablets/day) (n=800) until the end of delivery. The risk of GDM in pregnant women of the two groups was compared, the preventive effect of high-dose VitD supplementation during pregnancy on different subtypes of GDM was determined, and the effects of VitD supplementation on VitD nutritional status during pregnancy and birth outcome and health of offspring were explored, so as to provide evidence-based basis for rational VitD supplementation during pregnancy.

Official Title
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A Multicenter Randomized Controlled Study of Vitamin D Supplementation in Pregnant Women for the Prevention of Gestational Diabetes

Conditions
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Gestational Diabetes, Vitamin D

Intervention / Treatment
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* Drug: Vitamin D3
* Drug: The placebo(not contain vitamin D)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pregnant women who are 8 to 14 weeks pregnant ; ② 18 to 45 years old; ③ Pregnant women at high risk of GDM (meeting any of the following conditions) : A) BMI ≥24 kg/m2 before or during pregnancy; B) family history of diabetes or GDM; C) Previous pregnancy diagnosed as GDM; D) with a history of macrosomia (≥4000 g); E) A history of abnormal glucose tolerance: 5.7-6.4% hBA1c or 6.1-7.0 mmol/L fasting blood glucose. Sign informed consent. - Exclusion Criteria: Patients with a history of diabetes or currently diagnosed diabetes (including type 1 and type 2 diabetes); HBA1c ≥6.5% or fasting blood glucose & GT;7.0 mmol/L with obvious symptoms of diabetes; Patients with current or past abnormalities in calcium metabolism (hypoparathyroidism/hyperthyroidism, kidney stones), high urinary calcium or hypercalcemia; Daily VitD intake & GT;800 IU. ⑤ Suffering from serious chronic diseases (heart, lung, liver, kidney and other dysfunction) or mental illness; They cannot walk 100 meters safely; 7. Multiple pregnancies or assisted reproduction; ⑧ need complex diet; Cannot speak Mandarin fluently; ⑩ Those who are participating in other clinical trials or who are considered unsuitable for clinical trials by researchers for other reasons.

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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Randomized controlled study design
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental group<br>Take two tablets once a day.Each tablet contains 800 units of vitamin D3, for a total of 1600 units taken orally daily | Drug: Vitamin D3<br>* Participants began to take medication at 12 weeks of gestation, and participants in the second trimester began to take medication at the time point of enrollment.The dosage is 2 tablets per day, taken orally for 12 weeks.The drug in the intervention group was fat-soluble vitamin D3, which was produced by Sinopril Holding Starfish Pharmaceutical (Xiamen) Co., LTD. Each tablet contained 800 units of vitamin D3, vegetable oil and starch as auxiliary material.<br>|
| Placebo Comparator: Control Group<br>The control group received the same packaged, similar-looking, similar-tasting placebo from the same manufacturer, containing starch, peanut oil (no pharmaceutical value) | Drug: The placebo(not contain vitamin D)<br>* Pills that looked, colored and tasted like vitamin D in the control group, but contained only starch and vegetable oil and no vitamin D.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gestational diabetes | We will judge whether patients have gestational diabetes based on OGTT results (fasting, 1-hour, 2-hour blood glucose results) . | At 24-28 weeks of gestation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Newborn birth weight | Weight of newborn at birth | immediately after delivery | 
| Gestational age | Determine the gestational age of the woman and whether preterm birth exists | immediately after delivery | 
| Weight gain during pregnancy | Weigh the pregnant woman on the first day after delivery and subtract her weight before pregnancy from the birth examination book | First day after birth |