TG and hematocrit: Noteworthy are also the results from Sinsek et al. [115], who demonstrated a significant reduction in anti-TPO and anti-Tg amongst Turkish HT and GD patients with only one month of 1000 IU daily vitamin D. A meta-analysis by Zhang et al. [70] also showed that vitamin D supplementation reduces anti-TPO and anti-Tg titers, especially with a supplementation duration of over 3 months.