Analyses using Pearson correlation and linear regression coefficient was performed to assess the relationship between vitamin D and the study parameters and to evaluate the effect of vitamin D deficiency with some potentially effective parameters including mother age, gestational weeks, BMI, thyroid function tests (free T3, free T4, and TSH levels), thyroid autoantibodies (Anti-TPO, Anti-TG) and parathyroid hormones "Table 5". The gene discussed is TPO; the disease is vitamin D deficiency.