This inconsistency may be due to the limited number of RPL patients who were only positive for anti-TPO, not for other thyroid autoAbs (anti-thyroid-globulin antibody and TSH receptor autoAbs).In confirmation of this, Wang et al. have shown that there is a relationship between the titers of anti-thyroid-globulin antibody titers and the levels of serum 25(OH)D among females, but a weak association between anti-TPO titers and levels of serum 25(OH)D (34). Here, TPO is linked to thyroiditis.