Vitamin D Levels and Thyroid Function in Patients with Hyperthyroidism and Hypothyroidism

Abstract

Vikas Tiwari and Jaishree Tiwari

Background: Vitamin D deficiency is a widespread global health issue, affecting over one billion individuals. The biologically active form, 1,25-dihydroxyvitamin D [1,25(OH)2D], has been shown to regulate both innate and adaptive immune responses. Immune cells—including monocytes, macrophages, dendritic cells, and lymphocytes—express vitamin D receptors, suggesting a potential link between vitamin D status and autoimmune disorders, particularly thyroid diseases such as Graves’ disease and Hashimoto’s thyroiditis.

Methods: A prospective study was conducted at Arogyam Medical College and Hospital (AMCH), Roorkee, India, between March and July 2023. A total of 100 participants were enrolled. Venous blood samples were collected to assess serum vitamin D, triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) levels using chemiluminescence immunoassay. Statistical analyses were performed using SPSS version 20.

Results: Hypothyroid patients exhibited significantly lower mean serum vitamin D levels (16.27 ± 10.50 ng/mL) compared to controls (32.64 ± 2.26 ng/mL). In contrast, hyperthyroid patients had mean vitamin D levels within the normal range (39.35 ± 7.50 ng/mL), with no statistically significant difference from controls. TSH levels were markedly elevated in hypothyroid patients (10.03 ± 5.60 mU/L) and significantly suppressed in hyperthyroid patients (0.23 ± 0.12 mU/L), compared to controls (3.16 ± 1.40 mU/L).

Conclusion: The findings suggest a significant association between vitamin D deficiency and hypothyroidism, indicating a possible role in the pathogenesis of autoimmune thyroid disorders. Further large-scale, longitudinal studies are warranted to determine the therapeutic potential of vitamin D supplementation in thyroid disease management.

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