Thyroid function and its association with vitamin deficiencies: a case-control study in Duhok.

Abstract

Background: Hypothyroidism, characterized by insufficient thyroid hormone production, is a common endocrine disorder with significant health implications. Recent studies suggest that micronutrient deficiencies, particularly in vitamin D, vitamin B12, and ferritin, may contribute to thyroid dysfunction. This study aims to explore the relationship between hypothyroidism and these micronutrient deficiencies in a clinical setting.

Research design and methods: A case-control study was conducted between September and December 2024 at Public Central Health Lab., Duhok Azadi teaching Hospital, Iraq. A total of 885 participants were included, with 170 hypothyroid patients and 715 healthy controls. Serum levels of TSH, T3, T4, vitamin D, vitamin B12, and ferritin were measured. Multivariable regression analysis was used to examine the associations between thyroid function and micronutrient status.

Results: Hypothyroid patients had significantly higher TSH (9.4 ± 11.5 vs. 1.8 ± 0.8 mIU/L, p < 0.0001) and lower T4 (116.1 ± 28.6 vs. 129.2 ± 27.4 nmol/L, p < 0.0001) compared to controls. Vitamin B12 and ferritin levels were also lower in the hypothyroid group (p < 0.0001), while vitamin D showed no significant difference (p = 0.0524).

Conclusion: Hypothyroidism is associated with vitamin B12 and ferritin deficiencies, highlighting the importance of micronutrient in thyroid dysfunction management. Future studies should explore autoantibodies.

Clinical trial registration: http://duhokhealth.org/en/identifier/is/25092024-8-11.