“…Kim et al found that patients in the second lowest quartile of 25(OH)D had a greater occurrence of LNM (OR 2.03, 95% CI 1.19–3.44, P = 0.009) and lateral LNM (OR 5.12, 95% CI 1.68–15.59, P = 0.009) than those in the highest quartile ( 15 ). Cocolos et al described histopathologic features of 170 patients with differentiated thyroid cancer and found patients in T stage 4 had significantly lower 25(OH)D of 10.96 ng/mL than in T stage 1 of 18.24 ng/mL, suggesting that patients with aggressive tumors had lower circulating levels of 25(OH)D ( 29 ). On the contrary, Demircioglu et al ., Kuang et al and Ahn et al showed serum 25(OH)D levels were not associated with disease aggressiveness such as LNM, tumor size, lateral LNM, or multifocality ( 16 , 17 , 30 ).…”