The article presents data on the role of nutrients in the protection of the body against xenobiotics. The effect of the vitamin and amino acid complex (ascorbic acid (C), thiamine (B1), riboflavin (B2), niacin (PP), methionine) in relation to intoxication of animals (white outbred male rats) with hexachlorocyclohexane (HCH) was experimentally studied using cytochemical indicators of neutrophilic granulocytes’ enzymes: myeloperoxidase, acid phosphatase, nonspecific esterase. It was established that the activity of the enzymes in the group of animals that received the vitamin and amino acid complex 20 minutes before receiving HCH was 1.4–1.6 times higher, and the number of survivor animals in this group was 1.7 times higher than in the group receiving only pesticides.