The bioavailability of zinc can be influenced by several dietary factors, among them calcium level, which leads to zinc metabolism disturbance. Thus, the present study was under taken to evaluate the effect of zinc supplementation on zinc status and carbohydrate metabolism in non-diabetic and diabetic rats fed high-calcium diet.
Sixty male Wistar rats were randomly divided into six equal groups. The first and fourth groups were non-diabetic and diabetic controls respectively. The second, third, fifth and sixth groups were calcium, calcium + zinc, diabetes + calcium and diabetes + calcium + zinc groups, respectively. Diabetes in fourth, fifth and sixth groups were induced by alloxan. Calcium (35 mg/kg feed) as CaCO3 and zinc (231 mg/kg feed) as ZnSO4.7H2O in feed were supplemented to the animals in groups for 21 days.
High dietary calcium significantly decreased body weight gain, serum zinc, tissue zinc levels, alkaline phosphatase, lactic dehydrogenases and aldolase activities and led to an increase of cholesterol, transaminases and uric acid concentrations in both diabetic and non-diabetic rats. However, zinc supplementation in animals fed calcium assured a partial correction of the previous parameters.
The investigation revealed that zinc supplementation has a positive role against the negative effect of calcium, which provoked metabolic disturbance in diabetic and non-diabetic rats.