The objective of the study was to assess the effects of five vanadium organic complexes administered with small insulin injection, on V, Fe, Cu, Zn, Mn, Ca and K concentration in STZ (streptozotocin) diabetic rats tissues during a 5-week treatment with the tested complexes. In all groups of animals, metal concentration in a dry spleen samples was investigated by the proton induced X-ray emission (PIXE) method. Obviously, vanadium tissue concentration was higher in vanadium-treated rats. Concentration of vanadium in the spleen was x = 21.3 microg/g of dry sample. Vanadium administration influenced other metals concentration of rats tissues. The most pronounced influence of vanadium was observed on iron concentration in the spleen. All results were calculated for correlation between different groups of animals. Present study showed small interferences between trace element changes in diabetic, or non diabetic rats after vanadium treatment. Measured elements, especially zinc, manganese and copper, are co-factors of enzymes and their content changes can influence on organism homeostasis in diabetes treatment. Understanding and recognizing these relationship may permit better diabetes treatment in the future.