Abstract
Introduction: The relationship between vitamin D deficiency and thyroid gland disorders is controversial.
Objectives: Given the prevalence of vitamin D deficiency and the significance of thyroid disorders, the purpose of the study was to examine the relationship between anti-thyroid peroxidase (anti-TPO) antibody and vitamin D deficiency.
Patients and Methods: This cross-sectional study was conducted on 35 patients with vitamin D deficiency and 35 people as a control group with normal vitamin D considered more than 20 ng/mL. Serum TSH and anti-TPO antibody tests were assessed for all subjects in both groups. The level of 25 [OH] D3 less than 20 ng/mL was considered as the deficiency of vitamin D and the serum level of anti-TPO antibody more than 40 IU/mL as positive level.
Results: Mean age of patients with vitamin D deficiency was 37.00 ± 13.8 years and 46.3 ± 15.9 years in the control group. Mean age in the two groups was different (P=0.010). Around 51.4% of patients had vitamin D deficiency. There were no significant differences in TSH level among the groups (P=0.436). Anti-TPO antibody (anti-TPO Ab) level in 31.4% of the patients with vitamin D deficiency and in 11.4% of patients in the control group was positive with a significant difference (P=0.041). Logistic regression analysis showed the chance of positive anti-TPO Ab in people with vitamin D deficiency was 3.55% of the subjects without vitamin D deficiency (OR = 3.55, 95%, CI: 1.01-12.55, P=0.049).
Conclusion: Considering the greater chance (three-fold) of positive anti-TPO Ab titers in patients with vitamin D deficiency in this study, more interventional studies are suggested concerning the effect of vitamin D deficiency on anti-TPO Ab.