title: Calcium Plus Vitamin D Supplementation During the Third Trimester of Pregnancy in Adolescents Accustomed to Low Calcium Diets Does Not Affect Infant Bone Mass at Early Lactation in a Randomized Controlled Trial.
abstract: BACKGROUND
  Pregnancy and lactation in adolescents with low calcium intake may impair fetal growth and infant bone mass.
  
  
  OBJECTIVE
  We investigated the effects of calcium plus vitamin D supplementation during pregnancy in Brazilian adolescent mothers consuming low calcium diets (∼600 mg/d) on fetal biometry and infant bone mass, and the relation between infant and maternal bone mass during early lactation.
  
  
  METHODS
  Infants of mothers who received calcium (600 mg/d) plus cholecalciferol (200 IU/d) supplementation (n = 30) or placebo (n = 26) from 26 wk of gestation until parturition were studied. Fetal biometric measurements at 23 and 36 wk of gestation were obtained from medical records. Infant anthropometric and total body bone measurements [bone mineral content (BMC), bone area (BA), and bone mineral density (BMD)] at 5 wk postpartum were assessed by dual-energy X-ray absorptiometry. Maternal BMD z scores for total body, lumbar spine, total hip, and femoral neck at 5 wk postpartum were obtained. Group comparisons were adjusted for significant covariates.
  
  
  RESULTS
  Maternal mean serum 25-hydroxyvitamin D was 59 nmol/L at baseline in both groups. No differences in fetal measurements at 36 wk of gestation were observed between the groups, except for body weight and its increment from 23 to 36 wk, which were higher in the supplemented group (6.8%, P = 0.014 and 10.5%, P = 0.07, respectively). Infant BMC (61.1 ± 21.7 g), BA (167 ± 79 cm(2)), and BMD (0.385 ± 0.069 g/cm(2)) did not significantly differ between the groups. In the placebo group, infant BMC and BA were negatively correlated with maternal BMD z scores for total body (r = -0.40 and r = -0.47; P < 0.05) and hip (r = -0.41 and r = -0.46; P < 0.05). In contrast, no correlations were observed in the supplemented group.
  
  
  CONCLUSIONS
  Calcium and vitamin D supplementation of the adolescents studied resulted in higher fetal body weight at 36 wk of gestation and had no effect on infant bone mass at 5 wk postpartum. Because correlations between maternal and infant bone mass were evident only in the placebo group, infant bone mass appeared to be more dependent on maternal skeletal mass when calcium intake was low. This trial was registered at clinicaltrials.gov as NCT01732328.
authors.affiliation: Food and Nutritional Biochemistry Laboratory, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; Brazilian National Cancer Institute José Alencar Gomes da Silva, Rio de Janeiro, Brazil;
authors.forename: Maria Eduarda L
authors.initials: ME
authors.lastname: Diogenes
authors.affiliation: Nutrition Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil; and.
authors.forename: Flávia F
authors.initials: FF
authors.lastname: Bezerra
authors.affiliation: Nutrition Institute, Rio de Janeiro State University, Rio de Janeiro, Brazil; and.
authors.forename: Elaine P
authors.initials: EP
authors.lastname: Rezende
authors.affiliation: Food and Nutritional Biochemistry Laboratory, Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; School of Nutrition, University of the Republic, Montevideo, Uruguay cmarino@nutricion.edu.uy.
authors.forename: Carmen M
authors.initials: CM
authors.lastname: Donangelo
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D015519:Bone Density / Q000187:drug effects*; D001938:Brazil; D001942:Breast Feeding; D002136:Calcium, Dietary / Q000008:administration & dosage*; D019587:Dietary Supplements; D005260:Female; D005272:Femur Neck / Q000187:drug effects / Q000378:metabolism; D047109:Fetal Development; D006801:Humans; D007223:Infant; D007774:Lactation; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000378:metabolism; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D016037:Single-Blind Method; D014807:Vitamin D / Q000008:administration & dosage*
chemical_list: D002136:Calcium, Dietary; D014807:Vitamin D
keywords: adolescent mothers; calcium plus vitamin D supplementation; fetal skeletal growth; infant bone mass; lactation; pregnancy