## 1 Introduction  
In general, minerals constitute only 5% of a typical human diet, but they are essential for ensuring homeostasis in the body and, thus, health. Trace elements are minerals whose requirement for adults ranges from 1 to 100 mg daily or account for less than 0.01% of total body weight. According to the World Health Organization classification, chromium (Cr) and iodine (I) are classified as \"essential elements,\" and manganese (Mn)is a \"probably essential element\" for the proper development of living organisms and maintaining their vital functions [1; 2]. These elements are responsible for the appropriate course of some tissue processes and are building blocks of cell organelles, enzymes, and hormones. Disturbances in trace element homeostasis may result in the development of pathological states and diseases. Both deficiency and excess trace elements can harm living organisms when their efficient use and excretion mechanisms fail. An example of such an element is bromine (Br), which has a physiological effect on the body but can also negatively affect the health of humans and animals. Chromium (velogenic form III) is an element that takes part in the metabolism of carbohydrates (as Glucose Tolerance Factor GTF), proteins, and lipids (by activating enzymes involved in the metabolic pathways) in humans and animals. Its deficiency in the body contributes to increased blood glucose and cholesterol levels [3; 4; 5]. However, the polygenic form VI of chromium is a known toxic compound (especially hepatotoxic), which, due to its oxidizing potential, easily penetrates biological membranes and causes kidney damage, central nervous system diseases, and cancer in humans. In poultry nutrition, chromium is used under temperature stress conditions (which induce proteolysis, lipolysis, and glycogenolysis) due to its strong antioxidant effect, preventing lipid peroxidation [6]. Additionally, chromium enhances the action of insulin in the metabolism of carbohydrates and proteins [7]. The response of poultry organisms to feed supplementation with chromium depends on its chemical form. It has been shown that organic forms--chelates, e.g., yeast, picolinate, nicotine, propionate, methionine, and histidine--are less toxic and show greater bioavailability from feed [6; 8]. However, it should be noted that if heavy metals, such as chromium, are added to feed in amounts exceeding the required level [9], they may accumulate in the body tissues of poultry and humans consuming raw materials from poultry. Iodine is an essential human trace element for proper growth, brain development, immune system function, and thyroid hormone synthesis [10]. Therefore, insufficient or excessive iodine intake causes thyroid dysfunction and thus affects the body's metabolic functions [11]. Low iodine intake causes the development of iodine deficiency disorders (IDDs). Therefore, information on the actual content of iodine in food is the basis for creating recommendations regarding its consumption. It is also for implementing nutritional policy programs regarding food fortification with this element (mainly salt iodization), and is recommended by various international institutions [12; 13]. Manganese, its physiological role in the body, and its occurrence in goose meat have recently been the subject of an extensive systematic review [14]; therefore, we have referred to the data in the Results and Discussion section to avoid repeating this content. Bromine occurs naturally and is widely distributed in the environment as the inorganic anion, Br- Bromide can be found in food and feed due to natural occurrences, environmental contamination from anthropogenic activity, the use of certain biocidal products, and the administration of veterinary medicinal products in food-producing animals [15]. In the body, bromine is necessary for the enzymatic activity of peroxidase, which catalyzes the formation of sulfimine cross-links in collagen IV, essential for the structural integrity of basement membranes in tissues [15].