Vitamin D and selenium for type 2 diabetes mellitus with Hashimoto's thyroiditis: Dosage and duration insights.

This letter discusses the publication by Feng . Iodine, selenium, and vitamin D are closely associated with thyroid hormone production in humans; however, the efficacy of selenium and vitamin D supplementation for type 2 diabetes mellitus (T2DM) patients with Hashimoto's thyroiditis (HT) remains controversial. In the retrospective study we discuss herein, the authors highlighted significant improvements in thyroid function, thyroid antibodies, blood glucose, and blood lipid in T2DM patients with HT following addition of vitamin D and selenium to their antidiabetic regimens, underscoring the value of these supplements.