Rats toxicated with vanadium pentoxide showed drastic retardation in growth rate and supplementation of L ascorbic acid to these rats could not reverse this effect. The urinary excretion of L ascorbic acid and D glucuronic acid was decreased in the toxicated group of rats. Considerable lowering of L ascorbic acid content of the liver tissues of rats was observed under vanadium toxicated conditions. Supplementation of L ascorbic acid to this group raised the tissue Vitamin C reserve considerably. The normal histological patterns of the liver and kidney tissues of rats were severely disturbed under vanadium toxicated conditions. L ascorbic acid supplementation to this group of rats showed marked signs of restoration in this respect. Vanadium pentoxide treatment brought about a significant reduction in the biosynthetic capacity of L ascorbic acid, along with an enhanced utilization of this vitamin. Subsequent supplementation of L ascorbic acid to the toxicated group of rats was found to be effective in reversing these effects almost to the basal level.