Vitamin D supplementation in pregnancy-a survey of compliance with recommendations

Vitamin D deficiency in pregnancy has important maternal and fetal implications, with increased risk of developing gestational diabetes, preeclampsia, preterm birth and small for gestational age birthweight. It is recommended that every pregnant woman should take 5 μg (200 IU) of vitamin D per day during pregnancy and lactation.

This study aimed to determine the prevalence of women taking vitamin D supplementation and to identify the reasons for patients not taking supplementation within women attending an antenatal clinic in Dublin.

Survey of women attending the antenatal clinic of the National Maternity Hospital Dublin during 2 weeks in January 2017. Women were asked to record demographics, medical comorbidities and use of vitamin D supplementation or any other supplements in pregnancy, as well as reasons for non-use if appropriate.

Three hundred women were invited to participate and 175 completed the questionnaire (58%). Overall, 38.9% (n = 68) reported to be taking vitamin D supplementation. Of the women that reported not to be taking vitamin D supplementation, 57.9% (n = 62) were taking a pregnancy multivitamin that contained vitamin D, and 28.0% (n = 30) did not know that it was recommended in pregnancy. Therefore, a total of 45 women (25.7%) in our cohort were taking no vitamin D supplementation during pregnancy. There was no difference in non-use based on maternal age, BMI, parity, or country of origin.

Of the women surveyed, 74.3% reported supplementation with vitamin D, either knowingly or unknowingly. Public health initiatives need to utilize this relatively safe, low-cost intervention to maximize maternal and fetal health. This could reduce the rates of antenatal conditions with associated high morbidity and healthcare burden such as gestational diabetes and preeclampsia.