Maternal Vitamin D Status at Delivery and Allergic Outcomes in Early Adolescence: Prospective Findings from the KLOTHO Birth Cohort

BACKGROUND: Prenatal vitamin D exposure has been proposed as a potential determinant of immune development and subsequent allergic disease risk in offspring; however, long-term cohort data remain inconsistent. METHODS: [25(OH)D] measurements at delivery was used for vitamin D analyses. Allergic outcomes included asthma, allergic rhinitis, and eczema in offspring. Associations were evaluated using descriptive statistics, Spearman correlation analyses, and logistic regression models. RESULTS: = 0.31). Adjusted models including maternal age, pre-pregnancy body mass index (BMI), season of delivery, and ultraviolet exposure yielded similar non-significant findings, although analyses were limited by a reduced complete-case sample size. CONCLUSIONS: In this prospective cohort with follow-up into early adolescence, vitamin D status at delivery was not associated with asthma, allergic rhinitis, or eczema in offspring. These findings support a lack of statistically significant association; however, potential non-linear relationships should be interpreted cautiously, given the modest sample size.