Prevalence and determinants of vitamin D deficiency in the third trimester of pregnancy: a multicentre study in Switzerland.

Jean-Philippe Krieger,Begoña Lipp von Wattenwyl,Claudia Canonica,Therese Schröder,Sophie Cabaset,Ladina Christoffel,Katharina Quack Lötscher,Sabine Rohrmann,Aline Richard

doi:10.1017/s0007114517003634

Abstract

Vitamin D deficiency during pregnancy is associated with negative health consequences for mothers and their infants. Data on the vitamin D status of pregnant women in Switzerland are scarce. A three-centre study was conducted in the obstetric departments of Zurich, Bellinzona and Samedan (Switzerland) to investigate the prevalence and determinants of vitamin D deficiency (serum 25-hydroxyvitamin D (25(OH)D)<50 nmol/l) in 3rd-trimester pregnant women living in Switzerland (n 305), and the correlation between 25(OH)D in pregnant women and their offspring at birth (n 278). Demographic and questionnaire data were used to explore the determinants of vitamin D deficiency. Median concentration of serum 25(OH)D in the third trimester of pregnancy was 46·0 nmol/l (1st-3rd quartiles: 30·5-68·5), representing a 53·4 % prevalence of vitamin D deficiency. 25(OH)D levels in the umbilcal cord blood (median: 50·0 nmol/l; 1st-3rd quartiles: 31·0-76·6) strongly correlated with mothers' serum 25(OH)D (Spearman's correlation ρ=0·79, P<0·001). Multivariable logistic regression analysis showed that significant determinants of vitamin D deficiency in pregnant women were centre of study, country of origin, season of delivery and vitamin D supplement intake. Near-term BMI, skin colour, use of sunscreen and mothers' education, although each not individually significant, collectively improved the ability of the model to explain vitamin D status. Low vitamin D levels were common in this sample of pregnant women and their newborns' cord blood. Vitamin D supplement intake was the most actionable determinant of vitamin D status, suggesting that vitamin D supplementation during pregnancy should receive more attention in clinical practice.

Highlights

Vitamin D deficiency has been demonstrated in various populations and is considered a widespread health issue[1,2]
25-hydroxyvitamin D (25 (OH)D) concentrations in cord blood strongly correlate with maternal concentrations[7,8,9,10]: vitamin D deficiency in pregnant women may negatively impact fetal development
Vitamin D deficiency during pregnancy has been linked with several adverse health outcomes

Summary

Introduction

Vitamin D deficiency has been demonstrated in various populations and is considered a widespread health issue[1,2]. Some evidence indicates that babies’ body size, bone mineralisation or risk of acute lower respiratory infections may be affected by low vitamin D status during pregnancy[3,4]. While these associations require further confirmation, they raise the question of vitamin D sufficiency in pregnant women. In all populations studied, the reported prevalence of vitamin D deficiency was consistently high at or near term[15,16] These data, are not available for women in late pregnancy living in Switzerland.

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Results

Conclusion