Vitamin D status in children with Hashimoto thyroiditis.

OBJECTIVE: To investigate vitamin D status in children with Hashimoto thyroiditis. SUBJECTS AND METHODS: The study group consisted of 78 children recently diagnosed as Hashimoto thyroiditis and 74 subjects as the control group. Parameters of calcium metabolism, thyroid function tests, and 25-hydroxyvitamin D [25(OH)D] levels were measured. RESULTS: Vitamin D deficiency rate was significantly higher in the Hashimoto group compared with the control subjects (73.1% vs. 17.6%, p < 0.0001). In the Hashimoto group, mean 25(OH)D levels were significantly lower compared with the control group (31.2 +/- 11.5 versus 57.9 +/- 19.7 nmol/L, p < 0.001) and was inversely correlated with the anti-thyroid peroxidase (anti-TPO) levels (r = -0.30, p = 0.007). CONCLUSION: The higher vitamin D deficiency rates besides lower vitamin D levels in the Hashimoto group together with the inverse correlation between vitamin D and anti-TPO suggest that vitamin D deficiency may have a role in the autoimmune process in Hashimoto thyroiditis in children.