Infant Bone Growth, Lactation Bone Loss
Conditions
Brief summary
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.
Interventions
DIETARY_SUPPLEMENTCalcium plus vitamin D
Sponsors
Rio de Janeiro State University
Universidade Federal do Rio de Janeiro
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
FEMALE
Age
13 Years to 19 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | 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
| Measure | Time frame |
|---|---|
| Differences in maternal bone status according to vitamin D receptor (VDR) polymorphisms | 2, 5 and 12 months postpartum |
| 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 changes of maternal body composition postpartum between supplemented and placebo groups | 2, 5 and 12 months postpartum |
| Differences in infant body composition between supplemented and placebo groups | 2 months postpartum |
| Differences in human breast milk composition (nutrients and hormones) between supplemented and placebo groups | 2 months postpartum |
Outcome results
None listed