Krysiak et al. [101,102,103] conducted experiments amongst various HT populations in Poland (e.g., men with HT and alopecia [101], men with HT and testosterone deficiency [102], and euthyroid women with HT [102,103]), in which they assessed anti-TPO and anti-Tg levels after six months of 2000–4000 IU daily vitamin D supplementation. The gene discussed is TG; the disease is hematocrit.