The thyroid gland plays a crucial role in regulating metabolism and supporting development through the production of the hormones T4 and T3. These hormones are essential during childhood for nervous system myelination, physical growth, puberty, skeletal and dental maturation, and overall metabolic balance. In early infancy, when the hypothalamic–pituitary–thyroid axis is still immature, thyroid dysfunction can result in a range of long-term complications. The metabolism and action of thyroid hormones depend not only on iodine but also on other vital micronutrients, particularly selenium (Se). This narrative review aims to comprehensively examine the role of selenium in maintaining thyroid health from fetal life through adolescence. Selenium is a key micronutrient involved in thyroid development, hormone synthesis, antioxidant defense, and immune regulation, especially during pregnancy and childhood. Inadequate selenium levels may contribute to the onset, progression, and clinical management of various thyroid disorders, particularly hypothyroidism and autoimmune thyroid diseases. Although scientific evidence supports selenium’s critical functions in hormone metabolism and antioxidant protection, public awareness and monitoring of selenium intake remain insufficient. Beyond the need for further research, there is an urgent call for integrated public health strategies, ranging from sustainable, food-based approaches to targeted clinical screening and educational programs. Promoting awareness of selenium’s importance and incorporating selenium status into maternal and pediatric care protocols could play a significant role in preventing deficiencies and supporting long-term endocrine and neurodevelopmental health.

Early identification of vitamin D (VitD) deficiency in childhood is essential to support timely prevention and intervention strategies. Building on the previously validated pediatric EVIDENCe-Q questionnaire, this study aimed to refine the tool by integrating two patient-specific weighted variables, sun exposure during peak UVB hours, and BMI z -score categories, both recognized determinants of circulating 25-hydroxyvitamin D (25-OH-D) levels. A total of 354 children (190F/164 M) completed a 20-item pediatric VitD risk questionnaire. Serum 25-OH-D concentrations were available for 280 participants. Three scoring algorithms were evaluated: the unweighted standard model, the sun-weighted model, and the sun + BMI-weighted model. Statistical analyses included ANOVA, Pearson correlations, and receiver operating characteristic (ROC) analyses across biochemical thresholds of vitamin D deficiency and insufficiency (< 10, < 20, and < 30 ng/mL). Vitamin D deficiency (< 10 ng/mL) was observed in 6.8% of participants, while insufficiency affected 38.1% (< 20 ng/mL) and 74.7% (< 30 ng/mL). The unweighted standard model did not discriminate among vitamin D categories ( p = 0.622). In contrast, both weighted models showed significant discrimination (sun-weighted: p = 0.036; sun + BMI-weighted: p = 0.030). Only the sun + BMI-weighted model was significantly correlated with serum 25-OH-D levels ( r = − 0.13; p = 0.023). ROC analyses demonstrated limited accuracy for the unweighted model, whereas the weighted models showed moderate discriminatory ability, with the Sun + BMI-Weighted Model providing the strongest overall performance. Conclusions : Incorporating weighted patient-specific variables improves the discriminatory capacity of the pediatric EVIDENCe-Q. Despite moderate accuracy, particularly at lower thresholds, the refined questionnaire, especially the sun + BMI-weighted version, represents a practical, noninvasive screening tool to identify children at risk of hypovitaminosis D. What is Known: •  Vitamin D deficiency is highly prevalent in children worldwide, even in sun-rich regions, and is influenced by factors such as sun exposure and adiposity. • Serum 25-OH-D measurement is the diagnostic gold standard, while questionnaire-based tools offer a non-invasive but currently less accurate alternative in pediatrics. What is New: • Incorporating weighted factors for peak UVB sun exposure and BMI z-score signifi cantly improves the predictive performance of the pediatric EVIDENCe-Q. • The Sun + BMI-weighted model shows a significant correlation with serum 25-OH-D and enhances identification of children at risk of hypovitaminosis D (30 ng/mL).