ASSOCIATION OF VITAMIN D AND VITAMIN B12 DEFICIENCY WITH THYROID HORMONE PROFILE IN HYPERTHYROIDISM: A CASE–CONTROL STUDY

Abstract

Background: Hyperthyroidism is associated with increased metabolic demand and may influence micronutrient status. Vitamin D and Vitamin B12 deficiencies have been increasingly reported in thyroid disorders, but their relationship with thyroid hormone derangements requires further evaluation.

Objective: To assess and compare serum Vitamin D and Vitamin B12 levels in hyperthyroid patients and euthyroid controls, and to determine their association with thyroid hormone profile (TSH, FT3, FT4) in hyperthyroidism.

Methods: A hospital-based case–control study was conducted at NCRIMS and Hospital, Meerut, over 18 months. A total of 51 hyperthyroid cases and 69 euthyroid controls were enrolled. Baseline demographic data and clinical complaints were recorded. Serum Vitamin D, Vitamin B12, and thyroid function tests (TSH, FT3, FT4) were measured and compared between groups. Vitamin D deficiency was defined as <30 ng/mL and Vitamin B12 deficiency as <165 pg/mL. Correlation analysis assessed relationships between micronutrient levels and thyroid hormones.

Results: Cases and controls were comparable in demographic characteristics. Hyperthyroid patients commonly reported palpitations, weight loss, anxiety/irritability, heat intolerance, tremors, and fatigue. Mean Vitamin D and Vitamin B12 levels were significantly lower in cases than controls (p<0.0001 for both). Vitamin D deficiency was more frequent in cases (82.35%) than controls (21.74%), and Vitamin B12 deficiency was also higher in cases (92.16%) than controls (33.33%) (p<0.0001). Vitamin D and Vitamin B12 showed positive correlation with TSH and negative correlation with FT3 and FT4 (statistically significant).

Conclusion: Vitamin D and Vitamin B12 deficiencies are highly prevalent in hyperthyroid patients and are significantly associated with more severe thyroid hormone derangements, supporting the need for routine micronutrient assessment in hyperthyroidism.