Unveiling the Link Between Vitamin D, Hashimoto's Thyroiditis, and Thyroid Functions: A Retrospective Study

Area of Science:

• Endocrinology
• Immunology
• Nutritional Science

Background:

• Hashimoto's thyroiditis (HT) is an autoimmune condition.
• Genetic and environmental factors influence HT.
• Vitamin D's role in HT pathogenesis is under investigation.

Purpose of the Study:

• To investigate the association between vitamin D levels and Hashimoto's thyroiditis.
• To explore the relationship between vitamin D and thyroid function in HT patients.

Main Methods:

• Retrospective analysis of adult patients from an Endocrinology clinic.
• Measured serum levels of TSH, fT3, fT4, anti-TPO, anti-TG, and vitamin D.
• Classified HT based on autoantibodies; thyroid function (euthyroid/hypothyroid) and vitamin D status (deficient/insufficient/sufficient).

Main Results:

• Higher vitamin D levels observed in the HT group compared to the non-HT group (p < 0.001).
• Vitamin D deficiency was prevalent in both groups (65.5% non-HT, 62.1% HT).
• Euthyroid HT patients had the highest vitamin D levels; deficiency was more common in hypothyroid individuals.

Conclusions:

• No significant direct association found between vitamin D levels and HT or autoantibody positivity.
• Vitamin D deficiency is more prevalent in hypothyroid patients.
• Vitamin D may modulate immune activity or influence HT phenotype, despite not being directly involved in pathogenesis.