Vitamin D status in children with autoimmune thyroiditis

Abstract

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.

Study on Association between Vitamin D Deficiency and Autoimmune Hypothyroidism

“…The discovery of the vitamin D receptor (VDR) in monocytes, dendritic cells, and activated T cells highlighted the potential involvement of vitamin D in the immune system and in the pathogenesis of autoimmune diseases [7,8] . As an immune modulator, vitamin D reduces activation of the acquired immune system.…”

“…Active forms of vitamin D suppresses autoimmune disease pathology by regulating differentiation and activity of CD4+ T cells resulting in a more balanced T1/T2 response favouring less development of self-reactive T cells and autoimmunity. Therefore, vitamin D deficiency could theoretically increase the risk of autoimmune diseases such as type 1diabetes, rheumatoid arthritis, multiple sclerosis and Graves disease [2,7,8] . Although there is a lot of literature regarding the implication of vitamin D deficiency in the causation of cancer, autoimmune disorders, the physiological role of thyroid hormones in the regulation of vitamin D metabolism is still unclear.…”