TPO and ataxia telangiectasia: Further, we investigated if patients with AT and vitamin D deficiency (n = 21) had a worse hormonal profile compared to patients with AT and vitamin D sufficiency (n = 18), but we did not find significant differences between the two groups (TSH: 1.6 ± 0.8 vs. 1.7 ± 1.1 mcUI/mL, p = 0.39; FT3: 4.0 ± 0.8 vs. 3.7 ± 1.0 pg/mL, p = 0.30; FT4: 15.2 ± 3.0 vs. 14.3 ± 3.3 ng/dL, p = 0.31; TG-Ab: 293.7 ± 203.0 vs. 303.6 ± 210.1, p = 0.44; TPO-Ab: 252.4 ± 180.0 vs. 229.7 ± 193.3, p = 0.35).