Abstract
Background and Objective: Vitamin D deficiency is becoming a global problem and is linked to many immune disorders. In regard to autoimmune hypothyroidism, the data is still controversial. This study aimed to evaluate the link between autoimmune hypothyroidism, BMI and vitamin Din the female population of Saudi Arabia. Materials and Methods: This was a prospective cross-sectional study. Blood samples for vitamin D (25 OH) and thyroid function (TSH, T3 and T4) were taken from 51 autoimmune hypothyroid female patients (diagnosed after testing positive for autoimmune thyroid antibodies).Vitamin D deficiency was designated at levels lower than 20 ng mL(-1) and compared with thyroid function tests. Results: The results indicated low levels of vitamin Din up to 90% of these patients. Of the total 51 patients, 5 patients (9.8%) had normal vitamin D levels, 2 patients (3.9%) had insufficient levels and 44 patients (86.3%) had deficient levels. A significant inverse correlation was noted between vitamin D and TSH (r= - 0.28, p = 0.046) indicating an increase in TSH levels as vitamin D levels decrease. T3 and T4 were found to be in their normal range. In regard to body mass index (BMI), 10 of the 51 patients (9.6%) had normal body weight, 5 patients (9.8) were overweight and 36 patients (70.6) were obese. The results, however, were statistically non-significant. Conclusion: The results indicated that patients with autoimmune hypothyroidism suffered from hypovitaminosis D that was significantly associated with the degree and severity of the disease.