ASSOCIATION BETWEEN VITAMIN D STATUS AND THYROID AUTOIMMUNITY DURING EARLY PREGNANCY

To estimate if there is a relationship between vitamin D status and thyroid autoimmunity in the early stages of pregnancy, between January and March 2013, we investigated a total of 2636 women in first trimester of pregnancy coming for prenatal care. Serum levels of thyroid-stimulating hormone (TSH), free thyroxin (FT4), the thyroid peroxidase antibody (TPO-Ab) and 25-hydroxy vitamin D-3 [25(OH) D-3] were measured in all subjects. Spearman correlations were used to examine relationships between thyroid function indexes and vitamin D. Our results show that 80.88% of early-pregnant women had vitamin D deficiency (circulating 25(OH) D-3 <20ng/mL), indicating a high prevalence of vitamin D deficiency in Chinese pregnant women. Vitamin D status was not related to the presence of positive TPO-Ab. A positive association between FT4 and vitamin D was observed only in women with 25(OH)D-3 >= 20ng/mL. Vitamin D status was not related to thyroid autoimmunity during early pregnancy.