Vitamin D deficiency is associated with thyroid autoimmunity: results from an epidemiological survey in Tianjin, China

• Published in: Endocrine 2021-08, Vol.73 (2), p.447-454
• Main Authors: Fang, Fang, Chai, Yun, Wei, Hongyan, Wang, Kunling, Tan, Long, Zhang, Wanqi, Fan, Yuxin, Li, Fengao, Shan, Zhongyan, Zhu, Mei
• Format: Article
• Language: English
• Subjects: 25-Hydroxyvitamin D; Autoantibodies; Autoimmunity; CD4 antigen; Cell differentiation; Clinical trials; Cytokines; Diabetes; Endocrinology; Epidemiology; Helper cells; Humanities and Social Sciences; Internal Medicine; Iodide peroxidase; Lymphocytes T; Medicine; Medicine & Public Health; multidisciplinary; Original Article; Science; Supplements; Thyroglobulin; Thyroid; Thyroid gland; Thyroiditis; Vitamin D; Vitamin deficiency
• ISSN: 1355-008X; 1559-0100
• DOI: 10.1007/s12020-021-02688-z

Purpose The pathogenesis of Hashimoto’s thyroiditis (HT) is unclear, although some studies have identified an association between vitamin D deficiency and thyroid autoantibody positivity. This study aimed to investigate vitamin D status, and its relationships with thyroid autoantibody positivity and HT, via a large epidemiological survey. Methods The epidemiological survey was conducted in Tianjin, China. All participants underwent testing for serum 25-hydroxyvitamin D (25OHD), thyroid function, and thyroid autoantibodies, and some participants underwent testing to evaluate CD4 + T-cell differentiation and concentrations of related cytokines. Results The study included 1812 participants and revealed prevalences of 13.1% for thyroid peroxidase antibodies (i-TPOAb) and 14.0% for thyroglobulin antibodies (i-TgAb). Logistic regression analysis revealed that thyroid autoantibody positivity was associated with sex, age, and 25OHD classification. An increased likelihood of i-TPOAb positivity was associated with 25OHD deficiency (odds ratio [OR]: 2.428, 95% confidence interval [CI]: 1.383–4.261) and 25OHD inadequacy (OR: 1.198, 95% CO: 0.828–1.733; p  = 0.008). An increased likelihood of i-TgAb positivity was associated with 25OHD deficiency (OR: 2.366, 95% CI: 1.366–4.099) and 25OHD inadequacy (OR: 1.263, 95% CI: 0.883–1.807; p  = 0.009). Relative to healthy subjects, patients with HT had significantly higher proportions of Th1 and Th17 cells, as well as higher concentrations of related cytokines. Conclusions This study revealed that vitamin D deficiency was associated with thyroid autoantibody positivity, and that vitamin D deficiency seems to be involved in the pathological mechanism underlying HT. Large randomized controlled trials are needed to investigate the effects of vitamin D supplementation on HT.