Hypothyroidism and 25-Hydroxyvitamin D Correlation Study

Background: Thyroid disease is one of the most common illnesses in the UAE, which could be linked to vast numbers of people suffering from vitamin D deficiency. This study aimed to explore the association between serum 25(OH)D levels and thyroid function parameters in men and women with diagnosed hypothyroidism. Methods and Results: This cross-sectional observational study included 86 patients (78[90.7%] women and 8[9.3%] men) with diagnosed hypothyroidism. The patients were divided into two groups, male and female. These two groups were compared in terms of age, TSH, free-T4 (FT4), vitamin D, free-T3 (FT3), and body mass index (BMI). In addition, the correlation between levels of vitamin D and TSH was also examined in these two groups. The mean age of the patients was 27.5 years, and BMI was 28.00 kg/m2, indicating overweight. Vitamin D deficiency was found in 61(70.9%) patients and severe vitamin D deficiency in 10(11.6%) patients with hypothyroidism. 25(OH)D levels were significantly low in patients with high TSH levels, showing a weak negative correlation (r=-0.132, P=0.043). A negligible positive correlation was identified between 25(OH)D levels and FT4 r=0.089, P>0.05) and FT3 (r=0.071, P>0.05), and a negligible negative correlation with BMI (r=-0.059, P>0.05). Conclusion: There is a clear indication that vitamin D deficiency is prevalent in hypothyroid patients and that these subjects have lower levels of serum 25(OH)D. Suggesting that lower serum 25(OH)D is related to hypothyroidism and the deficiency in vitamin D plays a role in the development of the disease.