Maternal vitamin D status and infant outcomes in rural Vietnam: a prospective cohort study

PLoS One. 2014 Jun 26;9(6):e99005. doi: 10.1371/journal.pone.0099005. eCollection 2014.


Objective: Vitamin D deficiency affects 1 billion people globally. It has an important role in bone homeostasis, brain development and modulation of the immune system and yet the impact of antenatal vitamin D deficiency on infant outcomes is poorly understood. We assessed the association of 25- hydroxyvitamin D levels (25-OHD) in late pregnancy and early infant growth and developmental outcomes in rural Vietnam.

Design and methods: A prospective cohort study of 960 women who had previously participated in a double-blind cluster randomized controlled trial of antenatal micronutrient supplementation in rural Vietnam was undertaken. Maternal 25-OHD concentration was measured at 32 weeks gestation, and infants were followed until 6 months of age. Main outcome measures were cognitive, motor, socio-emotional and language scores using the Bayley Scales of Infant Development, 3rd edition, and infant length-for-age z scores at 6 months of age.

Results: 60% (582/960) of women had 25-OHD levels <75 nmol/L at 32 weeks gestation. Infants born to women with 25-OHD deficiency (<37.5 nmol/L) had reduced developmental language scores compared to those born to women who were vitamin D replete (≥75 nmol/L) (Mean Difference (MD) -3.48, 95% Confidence Interval (CI) -5.67 to -1.28). For every 25 nmol increase in 25-OHD concentration in late pregnancy, infant length-for-age z scores at 6 months of age decreased by 0.08 (95% CI -0.15 to -0.02).

Conclusions: Low maternal 25- hydroxyvitamin D levels during late pregnancy are of concern in rural Vietnam, and are associated with reduced language developmental outcomes at 6 months of age. Our findings strengthen the evidence for giving vitamin D supplementation during pregnancy.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • 25-Hydroxyvitamin D 2 / blood*
  • Adult
  • Child Development*
  • Dietary Supplements
  • Female
  • Humans
  • Infant, Newborn
  • Male
  • Pregnancy
  • Rural Population*
  • Vietnam
  • Vitamin D / administration & dosage
  • Vitamin D / therapeutic use
  • Vitamin D Deficiency / epidemiology*
  • Vitamin D Deficiency / prevention & control


  • Vitamin D
  • 25-Hydroxyvitamin D 2

Grant support

The original randomised trial was funded through a grant from the National Health and Medical Research Council of Australia. (Grant Number 628751). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.