Serum 25-Hydroxyvitamin D and Parathyroid Hormone Levels in Non-Lactating Women with Post-Partum Thyroiditis: TheEffect of l-Thyroxine Treatment

摘要

Vitamin D deficiency seems to be implicated in the onset and progression of some autoimmune disorders. No previous study has investigated vitamin D homeostasis in post-partum thyroiditis. We compared 25-hydroxyvitamin D and parathyroid hormone (PTH) levels between four groups of non-lactating women who gave birth within 12months before the beginning of the study: hypothyroid women with post-partum thyroiditis (group A; n=14), euthyroid females with post-partum thyroiditis (group B; n=14), women with non-autoimmune hypothyroidism (group C; n=16) and healthy euthyroid females without thyroid autoimmunity (group D; n=15). In the second part of the study, groups A and C were treated for 6months with l-thyroxine. Serum levels of 25-hydroxyvitamin D were lower, while PTH higher in patients with post-partum thyroiditis than in patients without thyroid autoimmunity. They were also lower (25-hydroxyvitamin D) or higher (PTH) in group A than in group B, as well as in group C in comparison with group D. l-thyroxine treatment increased 25-hydroxyvitamin D and reduced PTH levels only in hypothyroid women with post-partum thyroiditis. Baseline levels of 25-hydroxyvitamin D correlated with thyroid antibody titres, thyroid function and circulating PTH levels, while the effect of l-thyroxine on serum levels of this vitamin correlated with the changes in thyroid antibody titres and PTH levels. The results of our study suggest the association of vitamin D status with post-partum thyroiditis and l-thyroxine treatment of this disorder.