Vitamin D Level Among Patients with Different Thyroid Diseases

: To investigate the differences in vitamin D levels in patients with different types of thyroid disease and to investigate the factors influencing vitamin D levels in patients with thyroid disease, this study collected clinical data from 1603 patients with thyroid disease attending the Department of Endocrinology and Metabolism of the First People's Hospital of Yunnan Province and conducted a retrospective cross-sectional study. The clinical data of 1603 patients with thyroid diseases including Graves' disease (GD), subacute thyroiditis (SAT), autoimmune thyroid disease (AITD) and hypothyroidism (HP) were collected from the Department of Endocrinology and Metabolism of yunnan First People's Hospital. Gender, age, BMI, blood lipids, thyroid hormones, thyroid autoantibodies, and serum 25-hydroxyvitamin D(25(OH)D) levels were measured. Results: (1) The level of 25(OH)D in patients with different thyroid diseases was from high to low, in the following order: GD group (29.54±7.54 ng/ml), SAT group (28.01±7.14 ng/ml), AITD group (26.97±6.58 ng/ml), HP group (25.88±6.75 ng/ml), the differences were statistically significant (P<0.05). The 25(OH)D level in GD group was significantly higher than that in other groups (P<0.05), while the 25(OH)D level in HP group was significantly lower than that in SAT group (P<0.05). (2) The changing trend of thyroid hormone levels (T3, FT3 and FT4) was consistent with that of 25(OH)D (P <0.005). (3) 25(OH)D was established as the dependent variable with multiple linear regression equation, Y = 3.80 gender + 0.058FT3-0.036 age + 28.122(female as control group). Conclusions: There were significant differences in vitamin D levels among patients with thyroid diseases, with the highest vitamin D level in GD patients and the lowest vitamin D level in HP patients. The higher the thyroid hormone level, the higher the 25(OH)D, which may be related to the strength of the immune response or the effect of thyroid hormone on vitamin D synthase. Male and high levels of FT3 were associated with increased 25(OH)D levels in thyroid patients.