We studied the effects of a nutrient supplemented diet on the function of alveolar macrophages of silicosis rats and on the blastogenic response of lymphocytes, glutathione peroxidase (GSH-PX) activity, and lipid peroxidase (LPO) activity in the blood of silicosis patients. The results showed that a nutrient supplemented diet increased the phagocytosis rate (p < 0.01) and index (p < 0.05) of alveolar macrophages of silicosis rats. A nutrient supplemented diet also enhanced significantly the GSH-PX activity (p < 0.001) and the blastogenic response of lymphocytes (p < 0.01), and decreased substantially the LPO content (p < 0.05) in the blood of silicosis patients. We conclude that a nutrient supplemented diet may play an important role in antilipid peroxidation, decreased free radical reaction, stabilizing cell membrane, delaying lung fibrosis, and enhancing immune functions of the body.