Isolated Vitamin D Deficiency Is Not Associated with Nonthyroidal Illness Syndrome, but with Thyroid Autoimmunity

Muyesser Sayki Arslan,Basak Karbek,Mustafa Caliskan,Oya Topaloglu,Bekir Ucan,Mustafa Ozbek,Tuncay Delibasi,Erman Cakal,Melia Karakose,Esra Tutal,Mustafa Sahin,Zeynep Ginis

doi:10.1155/2015/239815

Abstract

Aim. This study aimed to compare thyroid functions, thyroid autoantibodies, and the existence of nonthyroidal illness syndrome (NTIS) according to vitamin D level. Materials and Methods. The study included age- and BMI-matched healthy volunteers with and without vitamin D deficiency. In addition, the nonthyroidal illness syndrome status was evaluated. Results. Anti-TPO positivity was significantly more common in those with severe and moderate vitamin D deficiency, as compared to those with a normal 25(OH)D level. Furthermore, TSH levels were significantly lower in those with severe and moderate vitamin D deficiency than in those with a normal 25(OH)D level. In addition, there was a significant weak inverse correlation between anti-TPO positivity and the 25(OH)D level and a positive correlation between the TSH level and 25(OH)D level. Only 1 thyroid function test result was compatible with NTIS among the participants with moderate vitamin D deficiency; therefore the difference was not significant. Conclusions. The prevalence of thyroid autoantibody positivity was higher in those with severe and moderate vitamin D deficiency than in those with a normal 25(OH)D level. Additional large-scale studies must be conducted to determine if vitamin D deficiency plays a causal role in the pathogenesis of Hashimoto's thyroiditis and NTIS.

Highlights

The best-known roles of vitamin D are in calcium metabolism and bone health; accumulating evidence shows that vitamin D has a variety of pro- and anti-inflammatory effects on the development of cancers, autoimmune diseases, and cardiovascular disorders
A study on the effect of vitamin D on monocyte expression of tumor necrosis factor-α (TNF-α) showed that 1,25(OH)2D3 could significantly suppress TNF-α, which plays an important role in the pathogenesis of autoimmune
The most important finding of the present study is that the prevalence of thyroid autoantibody positivity in healthy volunteers increased as the 25(OH)D level decreased

Summary

Introduction

The best-known roles of vitamin D are in calcium metabolism and bone health; accumulating evidence shows that vitamin D has a variety of pro- and anti-inflammatory effects on the development of cancers, autoimmune diseases, and cardiovascular disorders. In T helper 2 cells vitamin D increases both the proliferation of interleukin-4 and transforming growth factor that suppresses inflammatory T-cell activation [1, 2, 4]. These interactions are important in the pathogenesis of Hashimoto’s disease. Such proinflammatory cytokines as interleukin-6, TNF-α, and interleukin-1 have been suggested to be mediators in the pathogenesis of nonthyroidal illness syndrome (NTIS) [5]. A study on the effect of vitamin D on monocyte expression of TNF-α showed that 1,25(OH)2D3 could significantly suppress TNF-α, which plays an important role in the pathogenesis of autoimmune

Objectives

Methods

Results

Conclusion