1 Iodine in evolution of salivary glands and in oral health. Venturi S, Venturi M. Nutr Health. 2009;20(2):119-34. Iodine in Evolution of Salivary Glands and in Oral Health Sebastiano Venturi and Mattia Venturi Servizio di Igiene, ASL n. 1, Regione Marche, Pennabilli (PU) Italy, Corresponding address: Dr. Sebastiano Venturi - via Tre Genghe n. 2; 61016-Pennabilli (PU), Italy Tel : (+39) 0541 928205 . E-mail: venturi.sebastiano@gmail.com Short running title: Iodine and Oral Health ABSTRACT The authors hypothesized that dietary deficiency or excess of iodine (I) has an important role in oral mucosa and in salivary glands physiology. Salivary glands derived from primitive I-concentrating oral cells which, during embryogenesis, migrated and specialized in secretion of saliva and iodine. Gastro-salivary clearance and secretions of iodides are a considerable part of “gastro-intestinal cycle of iodides”, which constitutes about 23% of iodides pool in the human body. Salivary glands, stomach and thyroid share I-concentrating ability by sodium iodide symporter (NIS) and peroxidase activity, which transfers electrons from iodides to the oxygen of hydrogen peroxide and so protects the cells from peroxidation. Iodide seems to have an ancestral antioxidant function in all I- concentrating organisms from primitive marine algae to more recent terrestrial vertebrates. The high I-concentration of thymus supports the important role of iodine in the immune system and in the oral immune defence. In Europe and in the world, I-deficiency is present in a large part of the