The influence of high intake of vitamin C in the young growing rats under administration of nickel sulphate in toxic doses has been studied. Ingestion of nickel sulphate depresses the growth rates of rats, alters the vitamin C status in different tissues, inhibits certain enzymes of vitamin C metabolism and changes the activities of alkaline phosphatase and succinic dehydrogenase in the liver and kidney tissues. The acid phosphatase activity of liver, kidney and brain tissues of rats and glucose-6-phosphatase activity in liver, and serum GOT activity were stimulated, with reduction in the liver GOT activity. There is stimulation in the activities of rat brain inorganic pyrophosphatase and cholinesterase. Kidney tissues of rats were found to be more susceptible towards nickel toxicity as compared to the hepatic tissues in respect of morphological alterations. There is almost no alteration in the hepatic lipid composition. Administration of vitamin C in high doses to rats fed nickel salts in toxic doses can restore not only the growth rates but also certain enzyme activities to a significant extent.