Investigation of the effect of Vitamin D level in cord blood of newborn babies on regulatory T lymphocytes

Vitamin D plays a central role in calcium and phosphate metabolism and its essential for the proper development and maintanance of bone. Recent studies show that vitamin D is effective for different tissue functions in addition to bone metabolism. Vitamin D has immunoregulatory capacities vivo and in vitro. Regulatory T cells (Tregs) regulate effector T cell functions in order to prevent the autoimmune reactions that can occur because of immune tolerance impairment. In newborn and infancy, the important role of Tregs on the allergic disease such as atopic dermatitis and cow's milk allergy was demonstrated. They have also role to control inflammatory reactions against microorganism. Vitamin D induce dendritic cells(DC) in order to function Treg's modulation of immune tolerance (in allergy, inflamatory response and autoimmunity). In this study, we aimed to study association of cord blood vitamin D levels and the regulatory T cells. The study group comprised of 101 newborn whose gestational age was 38 weeks or more. Cord 25(OH)D levels were and CD4, CD25 were analyzed. Newborns were divided into two groups according to the 25(OH)D levels( <12 ng/ml) and 25(OH)D >12 ng/ml). There were no difference in white blood cell, total lymphocyte count, T helper, T reg cell percentage and number between two groups. There were also no correlations between vitamin D levels and T cell subset number and percentages. Keywords: Vitamin D, Regulatory T cells, cord blood, newborn