Vitamin D deficiency during pregnancy is a global health concern, contributing to adverse maternal and fetal outcomes. Despite its importance, limited data exist on vitamin D status and its determinants among pregnant women in Ethiopia. This study aimed to assess the prevalence and determinants of vitamin D deficiency among pregnant women in their first and second trimesters in Gondar Town, Ethiopia, 2024.

A facility-based cross-sectional study was conducted at the antenatal care unit of University of Gondar Comprehensive Specialized Hospital from January to March 2024.

Eligible participants were selected using a simple random sampling technique. Sociodemographic, behavioural and clinical data were collected through structured questionnaires and medical record reviews. Serum levels of vitamin D, calcium and alkaline phosphatase were analysed using the Beckman Coulter clinical chemistry analyser. Statistical comparisons between pregnant women in the first and second trimesters were performed using the independent t-test. Determinants of vitamin D deficiency were identified using multivariate logistic regression analysis.

384 pregnant women in their first or second trimester.

The prevalence of vitamin D deficiency (90 mm Hg) (AOR 0.28, 95% CI 0.11 to 0.70), lower dietary diversity (AOR 3.17, 95% CI 1.13 to 8.89), lower fish and fish oil consumption habit (AOR 3.01, 95% CI 1.03 to 8.77; AOR 12.27, 95% CI 1.50 to 100.42) were the key predictors associated with serum vitamin D defiency.

Nearly half of the pregnant women in Gondar Town exhibit vitamin D deficiency, showing a challenging public health concern. Thus, targeted interventions, such as dietary supplementation and lifestyle modifications, are urgently needed to address the problem and improve maternal and neonatal health outcomes.