1. Two-month old Wistar rats of both sexes received, as sole drinking liquid, an aqueous solution of ammonium metavanadate (AMV) at a concentration of 0.01, 0.05, 0.15 and 0.30 mg V/ml (corresponding to 0.2, 1, 3 and 6 mM solution) over 4 weeks. 2. In the animal groups receiving AMV solution of 0.15 or 0.30 mg V/ml concentrations to drink, a statistically significant decrease of the uptake of food and AMV solution was observed, as compared with food and water taken up in the same time by the control group. 3. Moreover, a distinct decrease of the L-ascorbic acid level was noted in the liver, kidneys, spleen and adrenals. These differences proved statistically significant in single cases of animals receiving a solution of 0.05 and 0.15 mg V/ml concentration and in all animals given the solution at the highest vanadium concentration.