(293) Predictors for correct vitamin D intake among pregnant women in the Netherlands

Background: Vitamin D deficiency is common among pregnant women. Inadequate levels of vitamin D during pregnancy have been associated with
negative consequences for both the mother and the infant. While vitamin D supplementation during pregnancy is recommended to prevent deficiency, the extent of adherence to these guidelines remains unclear. Understanding which determinants predict incorrect vitamin D intake during pregnancy can provide insight into which women require more information or guidance on selfcare during pregnancy.

Objectives: To assess pregnant women's adherence to vitamin D supplement guidelines and identify
predictors for incorrect intake during pregnancy.

Methods: This study utilized data from the Dutch Pregnancy Drug Register, and included 5,409 pregnant women. Self-reported data was collected for sociodemographic factors, lifestyle behaviors, pregnancy-related factors, paternal characteristics, and vitamin D intake. As indicators for correct vitamin D intake during pregnancy we estimated start, stop, and continuity of vitamin D intake. Potential predictors were maternal age, educational level, ethnicity, urbanicity, pre-pregnancy BMI, chronic illness, smoking behavior, alcohol use, illicit drug use, parity, history of miscarriage, history of preterm delivery, paternal age, paternal educational level, paternal ethnicity, any parental congenital anomaly. Predictors were analyzed using univariate and multivariate logistic regression models.

Results: A total of 2,049 women (37.9%) had incorrect vitamin D intake during pregnancy, most often because they did not take continuously used vitamin D throughout their entire pregnancy. Factors predictive of incorrect vitamin D intake were younger age, lower educational level, smoking, alcohol use,
unplanned pregnancy, and lower educational level of the biological father. Factors predictive of correct vitamin D intake were fertility treatment, chronic illness, pregnancy after more than one year of trying, and history of miscarriage.

Conclusions: To prevent vitamin D deficiency and improve maternal and infant health outcomes, health-promoting interventions targeting specific groups of pregnant women are needed, especially for those from lower socioeconomic backgrounds. These interventions should aim to ensure
adherence to vitamin D supplementation guidelines throughout the pregnancy.