Tehran University of Medical Sciences Journal of Family and Reproductive Health 1735-8949 19 1 2025 04 13 14 18 Mahbod Kaveh Bahrami Children's Hospital, Tehran University of Medical Sciences, Tehran, Iran Maryam Noory Bahrami Children's Hospital, Tehran University of Medical Sciences, Tehran, Iran Mohammad Kaji Yazdi Pediatric Hematology and Oncology Department, Bahrami Children's Hospital, Tehran University of Medical Sciences, Tehran, Iran Shima Jeiroodi Bahrami Children's Hospital, Tehran University of Medical Sciences, Tehran, Iran 2024 08 28 2025 01 26 Objective: To investigate the relationship between maternal and neonatal vitamin D serum levels in term infants with and without sepsis. Materials and methods: This is a case-control study with 320 participants which include , 80 mothers and babies with neonatal sepsis and 80 control mothers and babies without neonatal sepsis that included in  their quantitative vitamin D levels were compared with each other survey. Results: Demographic and clinical characteristics of infants (age at admission, gender) and mothers (age, education level) were recorded. Blood samples were taken to check serum vitamin D levels of these babies along with their mothers. Vitamin D levels were classified as deficiency less than 10 ng/ml, moderate deficiency 10-30 ng/ml, mild deficiency 20-30 ng/ml and normal 100-30 ng/ml.33 (41.3%) of the infants born in the neonatal sepsis group and 45 (56.3%) of the control infants were male. Using Fisher’s exact test, no significant difference was found between the two groups in terms of gender distribution, P=0.082. The median age of infants in the neonatal sepsis group was 5 (3-9) days and in the control group was 5 (4-6) days. The mean (age of mothers in the patient group was 29.6 (6.4) years and in the control group was 29.7 (5.6) years. The median range of maternal vitamin D levels in the neonatal sepsis group was 23.8 (15.0-30.0) and 28.6 (17.1-34.0) ng/ml in the control group. According to the Mann-Whitney U statistical test, the vitamin D level of mothers in the neonatal sepsis group was significantly lower than that of the group was the control (p=0.020). Conclusion: According to the result of the Mann-Whitney U test, the vitamin D level of mothers in the neonatal sepsis group was significantly lower than the control group (P=0.020). Mother’s vitamin D level maybe related to the incidence of neonatal sepsis. https://jfrh.tums.ac.ir/index.php/jfrh/article/view/2896 https://jfrh.tums.ac.ir/index.php/jfrh/article/download/2896/710