Effect of Calcium Plus Vitamin D Supplementation on Adolescent Mother and Infant Bone Health

Study Overview
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Brief Summary
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Pregnancy and lactation are periods of high calcium requirement. Inadequate maternal calcium intake and vitamin D insufficiency may adversely affect fetal and neonatal growth and maternal bone mass particularly in adolescent mothers. The investigators propose to evaluate the influence of calcium plus vitamin D supplementation during pregnancy on bone mass of lactating adolescent mothers with habitually low calcium and vitamin D, on fetal growth and neonate bone mass. Mothers are randomly assigned to receive daily calcium (600 mg) plus vitamin D3 (200 IU) supplement or placebo from mid gestation until parturition. Fetal growth parameters are assessed by standard ultrasound techniques at mid and late gestation. Maternal bone mass is assessed by dual energy x-ray absorptiometry (DXA) at 2 and 5 months postpartum and 6 months after weaning. Infant bone mass is assessed by DXA at 2 months postpartum.

Official Title
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Calcium Plus Vitamin D Supplementation During Pregnancy of Adolescent Mothers: Effects on Maternal and Infant Bone Mass, Calcium and Bone Metabolism and Breast Milk Composition

Conditions
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Lactation Bone Loss, Infant Bone Growth

Intervention / Treatment
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* Dietary Supplement: Calcium plus vitamin D


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 13-19 y old between 23 and 29 wk of gestation primiparous carrying single fetus intending to exclusively or predominantly breastfeed Exclusion Criteria: chronic health problems smokers users of nutritional supplements, except iron supplements provided during standard prenatal care

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 19 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
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: placebo<br>Inactive pill (microcrystalline cellulose and corn starch) taken daily | |
| Active Comparator: Calcium plus vitamin D<br>600mg of calcium and 200 international units (IU) vitamin D taken daily | Dietary Supplement: Calcium plus vitamin D<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in maternal bone mass changes postpartum between supplemented and placebo groups |  | 2, 5 and 12 months postpartum | 
| Differences in fetal growth and infant bone mass between supplemented and placebo groups |  | 2nd and 3rd trimester gestation and 2 mo postpartum | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in changes of bone and calcium related hormones and vitamin D status between supplemented and placebo groups |  | 2nd and 3rd trimester of pregnancy and 2, 5, 12 mo postpartum | 
| Differences in human breast milk composition (nutrients and hormones) between supplemented and placebo groups |  | 2 months postpartum | 
| Differences in maternal bone status according to vitamin D receptor (VDR) polymorphisms |  | 2, 5 and 12 months postpartum | 
| Differences in infant body composition between supplemented and placebo groups |  | 2 months postpartum | 
| Differences in changes of maternal body composition postpartum between supplemented and placebo groups |  | 2, 5 and 12 months postpartum |