Thyroid function is closely linked to nutrition through the diet–gut–thyroid axis. This narrative review highlights the influence of nutritional components and micronutrients on thyroid development and function, as well as on the gut microbiota. Micronutrients such as iodine, selenium, iron, zinc, copper, magnesium, vitamin A, and vitamin B12 influence thyroid hormone synthesis and regulation throughout life. Dietary changes can alter the gut microbiota, leading not just to dysbiosis and micronutrient deficiency but also to changes in thyroid function through immunological regulation, nutrient absorption, and epigenetic changes. Nutritional imbalance can lead to thyroid dysfunction and/or disorders, such as hypothyroidism and hyperthyroidism, and possibly contribute to autoimmune thyroid diseases and thyroid cancer, yet controversial issues. Understanding these relationships is important to rationalize a balanced diet rich in essential micronutrients for maintaining thyroid health and preventing thyroid-related diseases. The synthetic comprehensive overview of current knowledge shows the importance of micronutrients and gut microbiota for thyroid function and uncovers potential gaps that require further investigation.

Introduction: The mental health of medical students is a key factor for academic performance and the delivery of high-quality medical care in the future. Globally, medical students face numerous challenges that can affect their education. Living and studying facing the war has a crucial influence on medical students’ education and daily life. The study aimed to determine the psychological well-being and academic achievements of Ukrainian medical students who lived in the rear areas after the 18 months of the Russian–Ukrainian war.Methods: The cross-sectional study was conducted at I.Ya. Horbachevsky Ternopil National Medical University. We analyzed the psychological well-being and educational achievements of medical students from the second to fifth year of Medical Faculty using the self-report scales DASS-21 and IES-R. A total of 776 students filled out the DASS-21 scale and 491 IES-R scale, respectively.Results: Following the first 18 months of the war, 62.5, 59.6, and 58.8% of Ukrainian medical students self-reported signs of stress, anxiety, and depression, respectively. Severe and extremely severe depressive symptoms were observed in 25.6% of students, anxiety in 31.9%, and stress in 29.7%, with a higher prevalence among female students. Additionally, 44.2% of responders had significant symptoms of post-traumatic stress disorder, with the highest scores on the hyperarousal subscale (>37). Academic performance in 2023 was significantly lower compared to the pre-war period in 2019 (p < 0.001) (p = 0.000). The multiple linear regression analysis showed that academic performance was positively associated with depression (p = 0.003), hyperarousal (p < 0.001), anxiety (p = 0.03), and negatively associated with stress (p = 0.002).Conclusion: Ukrainian medical students in rear areas are facing various challenges, with war-related stressors having a profound impact on their mental health. Our findings have shown an increasing prevalence of anxiety, stress, depression, and symptoms of post-traumatic stress disorder, all of which may negatively affect academic performance. The educational process during wartime is important for facilitating qualified medical personnel and quality healthcare. Understanding the burden of war allows for the development of wellness programs that support student mental health in conflict zones.

Endocrine-disrupting chemicals (EDCs) are a heterogeneous group of natural and man-made chemicals from environmental sources that mimic natural hormones. They can have adverse effects on the morphology, physiology, growth, and development of different organs and systems, among these bone health can be affected too. EDCs work as agonists or antagonists on hormonal receptors in hormone-sensitive cells, influence gene expression by epigenetic mechanisms, stimulate or inhibit cell maturation, and affect the synthesis and metabolism of hormones. This review aims to summarize current evidence on the effects of exposure to EDCs on bone from early gestational to birth and long-term adverse effects. Single and mixtures of endocrine-disrupting chemicals can disrupt bone structure by modifying differentiation, increasing osteoclast activity, inhibiting pre-osteoblasts differentiation into mature osteoblasts and osteocytes, inducing changes in signaling pathways downstream of receptors, and ultimately remodeling and modifying the equilibrium between bone resorption and formation leading to increased bone resorption, morphological, and functional changes in bone maturation. EDCs can affect the IGF system, alkaline phosphatase, and osteocalcin gene expression. Findings are relative to both in vitro and in vivo studies. Studies have shown that prenatal exposure to EDCs leads to growth retardation, delayed ossification, and changes in bone length and size and in bone geometry with a lowering of bone mineral density and area-adjusted bone mineral content. Current knowledge on bone health, growth, mineral content, and development from molecular to clinical findings highlights how endocrine-disrupting chemicals can negatively affect these processes. Mechanisms, however, are not fully understood and need further investigation.

Purpose: Puberty is a key phase of growth and development, characterized by psychophysical transformations. It is driven by a combination of genetic, hormonal, and environmental variables. Epigenetic mechanisms, including histone post-translational modifications and chromatin remodeling, microRNAs, and DNA methylation, play important roles in orchestrating the developmental processes. We describe environmental factors that may interact with genetics, and factors influencing puberty onset, focusing in particular on epigenetic mechanisms that can help understand the timing and variations that lead to precocious or delayed puberty. Methods: We conducted a narrative review of associations between puberty and epigenetic mechanisms through a comprehensive search of PubMed, Scopus, and Web of Science databases. Results: The chromatin landscape of genes as KISS1 has revealed dynamic changes in histone modifications as puberty approaches, influencing the stimulation or inhibition of gene expression critical for reproductive maturation. MiRNAs regulate gene expression, whereas DNA methylation affects activation or repression of gene transcription of genes involved in pubertal timing. Moreover, studies in animal models have provided insights into the role of DNA methylation and miRNAs in brain sexual differentiation, highlighting the active involvement of epigenetic mechanisms in shaping sexually dimorphic brain structures. Conclusion: This review highlights the importance of understanding the complex interplay between epigenetic regulation and pubertal development, which can lead to new therapeutic options and shed light on the fundamental processes driving reproductive maturation.

Purpose: This work aims to determine the association between vitamin D deficiency and metabolic syndrome in overweight and obese adolescents from Ukraine.Methods: Anthropometric measurements were taken and general and biochemical examinations were performed on 136 obese and overweight adolescents and 60 adolescents with normal body weight. The vitamin D status was determined using 25-hydroxyvitamin D (25(OH)D) (calcidiol) levels in blood serum. To establish the factors influencing vitamin D status, the subjects were asked to answer a questionnaire and 2007 International Diabetes Federation diagnostic criteria were used to determine the incidence of metabolic syndrome. All research results were processed statistically.Results: A calcidiol sufficiency level was found in 3.9% of obese adolescents and 6.7% of overweight adolescents. Metabolic syndrome was found in 64.4% of obese adolescents with vitamin D deficiency, and in 26.2% of overweight adolescents. Factors associated with an increased risk of developing vitamin D deficiency in adolescents with metabolic syndrome included male sex (p=0.042), low income per family member (p=0.040), daily milk consumption of up to 1 cup per day (p=0.001), physical activity (p=0.001), duration of outdoor stays (p=0.001), and passive rest in front of a computer or television (p=0.001). Adolescents with metabolic syndrome were found predominance of body mass index (p<0.001), waist circumference (p<0.001), fasting blood glucose level (Р<0.001), and decreased calcidiol level (p=0.022). Among metabolic syndrome components, vitamin D deficiency was strongly associated with waist circumference and increased fasting blood glucose (p<0.05).Conclusion: Vitamin D deficiency is prevalent in overweight and obese adolescents from Ukraine. Vitamin D deficiency is associated with metabolic syndrome criteria in overweight and obese adolescents.