Trace Elements

Minerals are essential nutrients that play critical roles in human health by regulating various physiological functions. Examples include bone development, enzyme function, nerve signaling, and the immune response. Both the deficiencies and toxicities of minerals can have significant health implications. Deficiencies in macrominerals such as calcium, magnesium, and phosphate can lead to osteoporosis (associated with falls and fractures), cardiovascular events, and neuromuscular dysfunction. Trace mineral deficiencies, such as iron and zinc. Selenium deficiency impairs oxygen transport, immune function, and antioxidant defenses, contributing to anemia, delaying wound healing, and increasing susceptibility to infectious diseases. Conversely, excessive intake of minerals can have severe health consequences. Hypercalcemia can cause kidney stones and cardiac arrhythmias as well as soft-tissue calcification, whereas excessive iron deposition can lead to oxidative stress and organ/tissue damage. Maintaining adequate mineral levels through a balanced diet, guided supplementation, and monitoring at-risk populations is essential for good health and preventing disorders related to deficiencies and toxicities. Public health interventions and education about dietary sources of minerals are critical for minimizing health risks and ensuring optimal well-being across populations. While a comprehensive analysis of all macro and micronutrients is beyond the scope of this article, we have chosen to focus on calcium, magnesium, and phosphate. We summarize the consequences of deficiency and the adverse events associated with the overconsumption of other minerals.

Oxidative stress and its relationship to fertility and reproduction is a topic of interest in medicine, especially in the context of the effects of trace elements and micronutrients. Oxidative stress occurs when there is an excess of free radicals in the body, which can lead to cell and tissue damage. Free radicals are reactive oxygen species (ROS) that can be formed as a result of normal metabolic processes, as well as under the influence of external factors such as environmental pollution, UV radiation, and diet. Oxidative stress has a significant impact on fertility. In men, it can lead to DNA damage in sperm, which can result in reduced semen quality, reduced sperm motility and increased numbers of defective sperm, and free radical damage to sperm cell membranes causing a reduction in the number of available sperm. In women, oxidative stress can affect the quality of female reproductive cells, which can lead to problems with their maturation and with embryo implantation in the uterus and can also affect ovarian function and disrupt hormonal regulation of the menstrual cycle. A proper balance of trace elements and micronutrients is key to protecting against oxidative stress and maintaining reproductive health. Supplementation with appropriate elements such as zinc, selenium, copper, manganese, chromium, and iron can help reduce oxidative stress and improve fertility. This work discusses the effects of selected elements on oxidative stress parameters specifically in terms of fertility and reproduction.

The thyroid gland is an endocrine organ whose hormones enable the proper functioning of the organism. The normal function of this organ is influenced by internal and external factors. One of the external factors is trace elements. Trace elements in appropriate concentrations are necessary for the proper functioning of the thyroid. Fe, Cu, Mn, I, Zn, and Se are part of the enzymes involved in oxidative stress reduction, while Cd, Hg, and Pb can increase ROS production. Cu and Fe are necessary for the correct TPO synthesis. An imbalance in the concentration of trace elements such as Fe, Cu, Co, I, Mn, Zn, Ag, Cd, Hg, Pb, and Se in thyroid cells can lead to thyroid diseases such as Graves' disease, Hashimoto's thyroiditis, hypothyroidism, autoimmune thyroiditis, thyroid nodules, thyroid cancer, and postpartum thyroiditis. Lack of adequate Fe levels may lead to hypothyroidism and cancer development. The thyroid gland's ability to absorb I is reversibly reduced by Co. Adequate levels of I are required for correct thyroid function; both deficiency and excess can predispose to the development of thyroid disorders. High concentrations of Mn may lead to hypothyroidism. Furthermore, Mn may cause cancer development and progression. Insufficient Zn supplementation causes hypothyroidism and thyroid nodule development. Cd affecting molecular mechanisms may also lead to thyroid disorders. Hg accumulating in the thyroid may interfere with hormone secretion and stimulate cancer cell proliferation. A higher risk of thyroid nodules, cancer, autoimmune thyroiditis, and hypothyroidism were linked to elevated Pb levels. Se deficiency disrupts thyroid cell function and may lead to several thyroid disorders. On the other hand, some of the trace elements may be useful in the treatment of thyroid diseases. Therefore, the effects of trace elements on the thyroid require further research.

Background/Objectives: Zinc is an essential trace element involved in multiple aspects of immune function, including epithelial barrier integrity, innate and adaptive immune responses, regulation of inflammation and oxidative stress. Zinc deficiency has been associated with increased susceptibility to infections, particularly in the pediatric population. This narrative review aims to summarize and discuss current evidence on the role of zinc in the prevention and management of pediatric respiratory infections. Methods: A comprehensive literature review was conducted including randomized controlled trials, real-world studies, and international guidelines published in recent years. Both zinc monotherapy and multicomponent dietary supplements containing zinc were considered. Results: Evidence consistently supports a preventive role of zinc supplementation in reducing the incidence and burden of respiratory infections, particularly in children with recurrent disease and in zinc-deficient populations. Zinc-containing multicomponent supplements demonstrated significant reductions in infection frequency and duration, alongside improved patient and parent-reported outcomes, with a favorable safety profile. In contrast, data on zinc as an adjunctive treatment during acute infections, especially severe pneumonia, are less consistent, with limited impact on major clinical outcomes. The effectiveness of zinc appears to be influenced by treatment duration, baseline nutritional status, and formulation. Conclusions: In conclusion, zinc may represent a valuable component of preventive immune-nutritional strategies for pediatric respiratory infections, especially when administered as part of multicomponent formulations and over prolonged periods. While its role in acute disease management remains uncertain, optimizing zinc status may contribute to reducing infection recurrence and overall disease burden. Further well-designed trials are warranted to clarify optimal dosing, timing, and target populations.