Deoxynivalenol (DON, vomitoxin) is one of several human mycotoxins acquired through residues in foods of plant origin (cereals) and through foods of animal origin (kidneys, liver, milk, eggs). The aim of this study was to investigate the impact of deoxynivalenol-contaminated mouldy grain on the health status of rats and their ability to resist oxidative stress. The rats were fed a diet supplemented with DON along with organic and inorganic Zn(II), and vitamins for 28 days. The study focuses particularly on protective mechanisms and levels of reduced glutathione and metallothioneins (MT) against the adverse effects of xenobiotics. The highest concentrations of MT were detected in the tissues of kidneys ((6.70 ยฑ 0.05) ยตg g -1 ) and liver ((6.00 ยฑ 0.05) ยตg g -1 ), both of which are involved in detoxifying cationic xenobiotics. Lower concentrations were also detected in heart, brain, testes, and muscle tissues (approximately 3.0 ยตg g -1 ). Antioxidant capacity, glutathione-S-transferase, and liver enzymes activity were also studied. In conclusion, MT may play an important role in the detoxification of mycotoxins. Even though its role is not fully understood, MT are crucial for the redistribution of ions important for transcription factors and interaction with reactive oxygen species that form mycotoxins.