During pregnancy, calcium and vitamin D are transported from the mother to the fetus, contributing to the mineralisation of the fetal skeleton and neonatal vitamin D status. The dietary requirements for calcium and vitamin D in non-pregnant adults have been extended to pregnancy, on the basis of insufficient evidence to support pregnancy-specific values(1). However, calcium and vitamin D intakes are low in Irish women(2) and there is currently no recommendation for supplementation of these nutrients during pregnancy in Ireland. The aim of this study was to describe the habitual calcium and vitamin D intakes among pregnant women in Ireland using data collected from women participating in the DMAT randomised controlled trial (RCT) [Nutritional Requirements for Vitamin D in Pregnant Women (DMAT), NCT02506439].
Participants (n = 100) were healthy Caucasian women who were having a low-risk pregnancy and receiving antenatal care at the Cork University Maternity Hospital. Dietary vitamin D and calcium intakes were assessed at baseline (⩽18 weeks gestation) using a quantitative food frequency questionnaire(Reference Kiely, Collins and Lucey3). Mean ± SD total calcium intake was 1227 ± 491 mg/d, and 26 % of women consumed calcium in supplemental form (dose range = 22–500 mg/d). Mean ± SD total vitamin D intake was 10·8 ± 5·3 µg/d. Sixty-eight percent of women reported taking a vitamin D-containing supplement (dose range = 2·1–10 µg/d).
Table 1. Sources of vitamin D and their contribution to total vitamin D intake
The prevalence of antenatal multivitamin use was high in this sample and was the major contributor to overall vitamin D intake. Among women not consuming a vitamin D-containing supplement, mean daily intakes were approximately half the current EAR (4·9 ± 3·4 µg/d). These findings highlight the current importance of nutritional supplements to meeting dietary requirements for vitamin D in pregnancy. These data will contribute to analysis of the dose response of 25(OH)D to total vitamin D intake in the DMAT RCT, which aims to inform vitamin D requirements during pregnancy and the neonatal period, and will report in full during winter 2016.
