Supplémentation de la vitamine D chez les patients présentant une maladie auto-immune dysthyroidienne (Hashimoto et Grave-Basedow). Etude systématique.

Abstract

Introduction: Vitamin D deficiency may be an important environmental factor involved in both the development and perpetuation of autoimmune diseases. Many of studies have shown a relationship between low vitamin D levels and the development of autoimmune thyroid diseases (AITM) such as Hashimoto's thyroiditis (HT) and Graves' disease (GB).The objective of this systematic review is to analyse recent data confirming the presence or absence of association between the level of vitamin D25-OH and dysthroid autoimmune diseases HT and GB, and to verify if vitamin D-25OH supplementation will exert a beneficial effect in HT and GB disease. Methods: The present work is a systematic review; the publications taken are observational, systematic or Meta-analytic studies, with different languages. Our work is divided into two main parts, the first one dealt with the involvement of vitamin D and HT; the second part verified the involvement of vitamin D in GB, ensuring the beneficial role of vitamin D supplementation in both pathologies. Results: The systematic review of 27 papers on 25 OH vitamin D and autoimmune thyroid disease showed that HT patients have low vitamin D, FT3 and FT4 and high TSH, TPO-Ab, TG-Ab, compared to controls. More than half of the population is affected by hypovitaminosis (˂30ng/ml). A weak significant association between low vitamin 25 OH D, TG-Ab, and TSH is observed in one-third of the analysed studies. Moreover, a significant positive effect of vitamin D supplementation on vitamin status in the majority of the analysed studies, with a significant decrease of antithyroid antibodies (TPO-Ab and TG-Ab) and TSH. On the other hand, GB patients had a weak negative significant association between vitamin D, TR-Ab, antithyroid antibodies TPO-Ab and TG-Ab, and thyroid volume in half of the studies analysed. Thus there was a positive impact of vitamin D supplementation on vitamin status in 70% of the studies, as well as a significant decrease in antithyroid antibodies and TR-Ab in 50% of the works. Conclusion: Hypovitaminosis less than 30 ng /ml is observed in most patients with HT or GB. Vitamin D supplementation increases vitD 25OH levels with a decrease in thyroid autoantibodies, TSH (HT) and TR-Ab (GB).