Immune responses play a key role in the survival of all living things. Intake of inorganic materials is of critical importance in living organisms because of their participation in metabolism and some component of cells. Iron (Fe), magnesium (Mg) and selenium (Se) were selected for this study because of their participation in critical constituents of cells, such as nucleic acids and enzymes in living organisms, and their indirect and direct effects on immunity. Although the separate effects of these inorganic materials are known, there is no study on their combined effects. Galleria mellonella, which is used as a model organism, is frequently used in evaluating of effects of human pathogens due to its various properties. Total hemocyte counts and encapsulation-melanization responses are the most commonly observed parameters when examining the immune responses of this model organism. In our study, the effects of the selected inorganic materials added in the ratio of 0.1%, 0.25%, 0.5% and 1% in the nutrient content of G. mellonella on the immune responses of this organism were investigated. As a result of the study, it was found that only 0.25% of the doses increased the hemocyte count and that the other doses significantly decreased compared to the control group. However, it was determined that 0.5% and 1% feeding caused a significant decrease in both hemocyte count and encapsulation-melanization responses. According to our findings, the nutrients which have over a certain dose by inorganic substances have negative effects on immunity.