Evaluation of the Relationship Between Umbilical Cord Blood Vitamin D Levels and Thymus Size in Healthy and Term Newborns

Summary Purpose: Thymus is a primary lymphoid organ which contains the vitamin D receptor. Vitamin D has an immunological regulatory effect on the adaptive and innate immune system. The aim of this study was to determine the relationship between cord blood 25-hydroxy vitamin D levels and thymus size. Materials and Methods: 149 babies were included in the present study. The cord blood 25-hydroxy vitamin D level was measured. Mothers’ and infants’ features were recorded. Thymus volume were evaluated with ultrasonography. The thymic index and thymus/weight index were calculated. Results: In the case of irregular use or non-use of maternal vitamin D, the likelihood of vitamin D deficiency in the cord blood was higher (p=0,027). No difference was observed between the thymic index measurements and maternal vitamin D use and cord blood vitamin D level. Conclusion: There was no relationship between cord blood vitamin D level and thymus size