Selenium: An Element of Life Essential for Thyroid Function

Abstract

Selenium (Se), a microelement essential for life, is critical for homeostasis of several critical functions, such as those related to immune–endocrine function and signaling transduction pathways. In particular, Se is critical for the function of the thyroid, and it is particularly abundant in this gland. Unfortunately, Se deficiency is a very common condition worldwide. Supplementation is possible, but as Se has a narrow safety level, toxic levels are close to those normally required for a correct need. Thus, whether the obtaining of optimal selenium concentration is desirable, the risk of dangerous concentrations must be equally excluded. This review addressed the contribution by environment and food intake on Se circulating levels (e.g., geographical factors, such as soil concentration and climate, and different quantities in food, such as nuts, cereals, eggs, meat and fish) and effects related to its deficiency or excess, together with the role of selenium and selenoproteins in the thyroid pathophysiology (e.g., Hashimoto’s thyroiditis and Graves’ disease).

Associations of Dietary Copper, Selenium, and Manganese Intake With Depression: A Meta-Analysis of Observational Studies

“…In addition, copper plays a significant role in signaling involving mitophagy, bioenergetics, and dynamics and mitochondrial function, which determine cellular fate by metabolic reprogramming ( 9 ). In addition, selenium is severed as an essential micronutrient that maintain the different cellular functions, such as immune-endocrine function and signaling transduction pathways ( 10 ). Moreover, selenium incorporates into selenoproteins and selenium-dependent enzymes (e.g., glutathione peroxidases), which is closely related to intracellular redox regulation and modulation ( 11 ).…”

Associations of the Dietary Iron, Copper, and Selenium Level With Metabolic Syndrome: A Meta-Analysis of Observational Studies

“…Micronutrients are important factors for cellular and biochemical functions (release of energy for synthesis and movement) (12). Iron, copper, and selenium are considered to be significant micronutrients and their dietary sources are meat, seeds, heme, tea, milk, nuts, cereals, eggs, fish, and so on (13)(14)(15)(16)(17)(18). Iron is one of the most abundant elements, which plays a significant role in various cellular processes, such as irondependent signaling, cellular respiration, DNA replication and synthesis, nucleic acid repair, and energy metabolism (19)(20)(21).…”

“…In addition, copper plays an essential role in mitochondrial function and signaling involving mitophagy, bioenergetics, and dynamics, which affect cell fate by metabolic reprogramming ( 26 ). Selenium, also an essential micronutrient, is necessary to maintain the different cellular functions, such as signaling transduction pathways and immune-endocrine function ( 18 ). Moreover, selenium incorporates into selenoproteins and selenium-dependent enzymes (e.g., glutathione peroxidases), which are involved in intracellular redox regulation and modulation ( 27 ).…”

Thyroid Dysfunction and COVID-19: The Emerging Role of Selenium in This Intermingled Relationship

“…Nonetheless, additional biomarkers and related pathways may explain, almost in part, the intermingled relationship between COVID-19 and thyroid dysfunction. In this context, selenium (Se), a trace microelement critical for the function of the thyroid gland, is emerging as a determinant for risk, severity, and clinical outcomes in SARS-CoV-2 infection [ 7 , 8 ]. In fact, Se is a potent antioxidant and plays a beneficial role in terms of the occurrence and severity of various viral infections (e.g., influenza, hepatitis), with the majority of its effects derived from its incorporation into selenocysteine (Sec), a component of selenoproteins [ 8 ].…”