Article

Maternal vitamin D status and calcium intake interact to affect fetal skeletal growth in utero in pregnant adolescents

Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
American Journal of Clinical Nutrition (Impact Factor: 6.92). 04/2012; 95(5):1103-12. DOI: 10.3945/ajcn.111.023861
Source: PubMed

ABSTRACT Maternal calcium intake and vitamin D status may affect fetal bone development.
This study was designed to examine relations between maternal calcium intake, 25-hydroxyvitamin D [25(OH)D] status, and fetal bone growth across pregnancy.
This was a prospective longitudinal design. Maternal 25(OH)D, parathyroid hormone, and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] were determined at midgestation (∼26 wk) and at delivery in 171 adolescents (≤ 18 y). Dietary recalls and fetal sonograms were performed up to 3 times across gestation, and fetal femur and humerus z scores were generated.
Fetal femur and humerus z scores and neonatal birth length were significantly greater (P < 0.03) in adolescents consuming ≥ 1050 mg than in those consuming <1050 mg Ca/d. Maternal 25(OH)D > 50 nmol/L was significantly positively associated with fetal femur and humerus z scores (P < 0.01). When maternal smoking, height, race, weight gain, and gestational age were controlled for, these relations remained significant. Interactions between calcium intake and 25(OH)D were evident. Calcium intake was associated with fetal femur z scores and birth length only when maternal 25(OH)D was ≤ 50 nmol/L (P < 0.05). Similarly, maternal 25(OH)D was associated with fetal femur and humerus z scores only when maternal calcium intake was <1050 mg/d (P < 0.03).
Optimal calcium intake and adequate maternal vitamin D status are both needed to maximize fetal bone growth. Interactions between these nutrients were evident when either calcium or vitamin D status was limited. Improving maternal calcium intake and/or vitamin D status during pregnancy may have a positive effect on fetal skeletal development in pregnant adolescents.

0 Followers
 · 
98 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Context:Vitamin D deficiency during pregnancy may be associated with suboptimal fetal growth, but direct evidence is lacking.Objectives:The aim of the study was to validate a method for fetal femur volume (FV) measurement using three-dimensional ultrasound and to detect correlations between FV and maternal vitamin D concentration.Design, Setting, and Participants:A novel method for assessing FV consists of three ultrasound measurements-femur length, proximal metaphyseal diameter (PMD), and midshaft diameter-and a volume equation; this was validated by comparing ultrasound to computed tomography measurements in six pregnancies after mid-trimester termination. This method was then applied in a cohort of healthy pregnant women participating in the Southampton Women Survey. Fetal three-dimensional ultrasound and maternal 25-hydroxyvitamin D [25(OH)D] levels were performed at 34 wk; dual-energy x-ray absorptiometry of the newborn was performed shortly after birth. Univariate and multiple linear regression analyses were performed between maternal characteristics and fetal outcomes.Main Outcome Measures:We performed ultrasound measurements of the fetal femur.Results:In 357 pregnant participants, serum 25(OH)D correlated significantly with FV (P = 0.006; r = 0.147) and PMD (P = 0.001; r = 0.176); FV also demonstrated positive univariate correlations with maternal height (P < 0.001; r = 0.246), weight (P = 0.003; r = 0.160), triceps skinfold thickness (P = 0.013; r = 0.134), and a borderline negative effect from smoking (P = 0.061). On multiple regression, independent predictors of FV were the maternal height and triceps skinfold thickness; the effect of 25(OH)D on FV was attenuated, but it remained significant for PMD.Conclusion:Using a novel method for assessing FV, independent predictors of femoral size were maternal height, adiposity, and serum vitamin D. Future trials should establish whether pregnancy supplementation with vitamin D is beneficial for the fetal skeleton, using FV and PMD as fetal outcome measures.
    The Journal of Clinical Endocrinology and Metabolism 09/2012; 97(11). DOI:10.1210/jc.2012-2538 · 6.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Vitamin D is a key nutrient for both healthy children and those with chronic illnesses. Understanding its roles in health and disease has become one of the most important issues in the nutritional management of children. Formal guidelines related to nutrient requirements for vitamin D in healthy children, recommending dietary intakes of 400 IU per day for infants and 600 IU per day for children over 1 year of age, were released by the Institute of Medicine in November 2010. However, application of these guidelines to children with acute and chronic illnesses is less clear. In this Review, we consider major illness categories and specific examples of conditions in children that might be affected by vitamin D. This information can be used in developing both model systems of investigation and clinical trials of vitamin D in children with acute and chronic illnesses.
    Nature Reviews Endocrinology 02/2013; 9. DOI:10.1038/nrendo.2012.259 · 12.96 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In a recently published prospective study, Villamor et al. found increased risk of early menarche in vitamin D-deficient girls compared to vitamin D-sufficient girls in Bogota, Columbia. The association was not fully explained by differences in body mass index-for-age z-scores. The mechanism for the association, if real, has not been elucidated, but could potentially involve vitamin D receptor polymorphisms. Early menarche and vitamin D deficiency are both associated with poor health outcomes, and further exploration of their association is important for women's health.
    Nutrition Reviews 03/2013; 71(3):189-93. DOI:10.1111/nure.12015 · 5.54 Impact Factor
Show more