This study was conducted to evaluate acid-base status and fructose diphosphatase (FDPase) activity in 40 (4 groups of 10) male Wistar rats. One group of rats was left untreated as control, fed a standard diet, and given distilled water. Periodontitis model induced with 5 mg/kg NH4Cl (group 1), exposed to sodium fluoride (NaF) at the concentration 5 mg/l (group 2), exposed to NaF (5 mg/l) and supplemented with minerals and vitamins (group 3). At the termination of experimental period (30 days) the pH and pCO2 value of arterial blood were analysed. Then, the FDPase activity in the hemogenized heart, kidney, liver, mandible, pelvis, and teeth were determined by measuring inorganic phosphate that converts from fruc-tose-1.6-diphosphate and using spectrophotometer at 350 nm. The differences in the acid-base status and FDPase activity in the groups 1 and 2 were statistically significant in comparison with the control and group 3 (P<0.001). Increased FDPase activities are associated with acid-base status. The minerals and vitamins supplementation proved to restore acid-base balance, reduce toxicity and establish steady enzyme activity, which has not been previously reported.