Publication:

Vitamin D status in children with autoimmune thyroiditis

Background Deficiency of 25 hydroxyvitamin D has been linked with predisposition to autoimmune disorders. Also, vitamin D has been found to be a causal factor in many autoimmune diseases. Objective of the study was to investigate vitamin D status in children with autoimmune thyroiditis attending endocrinology OPD at a tertiary centre in southern India.

Methods It is a case control study done in which 75 children (70 female, 5 male) with age and sex matched healthy controls were chosen. Free thyroxine, TSH, anti TPOAb, anti TGAb, 25 hydroxyvitamin D, serum calcium, phosphorus, alkaline phosphatase levels were estimated in both cases and control subjects. Children with anti TPO or anti TG positivity were divided into four groups based on their level of antibody titers.

Results The mean age in cases was 9.8±0.34 years. 25(OH)D levels were significantly lower in cases (15.07±1.14 ng/ml) compared to controls (17.82±1.13 ng/ml) (p<0.0006). Mean serum calcium levels in cases (9.35±0.16 mg/dl) were significantly lower when compared to controls (9.73±0.14 mg/dl) (p<0.0005). Similarly mean serum alkaline phosphatase level in cases (184.97±11.10 IU/L) were significantly elevated when compared with controls (122.37±6.82 IU/L) (p<0.0001). However, there was no significant difference in serum phosphorus levels between cases (4.42±0.10 mg/dl) and controls (4.43±0.14 mg/dl) (p=0.83). There was no significant difference in vitamin D level among the groups in both anti TPO (p< 0.283) and anti TG (p<0.148).

Conclusions The significant decrease in vitamin D levels in cases signifies that 25(OH)D may be an independent causal factor related to the autoimmunity in thyroid diseases.