Abnormality of serum 25(OH) D level and its associations with thyroid hormones and auto-antibody in patients with Graves disease

Objective To investigate the effect of serum 25-hydroxyvitamin D[25(OH) D]level,a principal maker assessing vitamin D level in vivo,on thyroid hormones and its auto-antibody in patients with Graves disease (GD) . Methods Thirty GD patients (GD group) and 20 healthy subjects (control group) were enrolled in this study. Serum 25(OH) D,thyrotrophin receptor antibody (TRAb) ,free triiodothyronine (FT3 ) ,free thyroxine (FT4 ) and thyroid-stimulating hormone (TSH) in GD group as well as serum 25(OH) D in control group were detected. The associations between serum 25(OH) D level and FT3 ,FT4 ,TSH,TRAb were analyzed. Results Serum 25(OH) D level in GD group was significantly lower than that in control group (P0. 01) . In GD group,the patients with 25(OH) D deficiency (vitamin D deficiency group) or insufficiency (vitamin D insufficiency group) were 28 cases (93. 33% ) . The 25(OH) D and TSH levels in vitamin D deficiency group were significantly lower than those in vitamin D insufficiency group (all P0. 01) ,while the levels of TRAb,FT3 and FT4 were significantly higher than those in vitamin D insufficiency group (all P0. 01) . In GD group,the levels of 25 (OH) D and TSH were positively related (r=0. 381,P0. 05) ,but 25(OH) D level and levels of FT4 (r=-0. 64,P0. 01) , FT3 (r=-0. 73,P0. 01) and TRAb (r=-0. 58,P0. 01) were negatively related,respectively. Conclusions Vitamin D deficiency or insufficiency universally exists in GD patients,and its level is closely correlated with thyroid hormones levels and thyroid autoimmunity reaction.