A test in the diagnosis of marginal zinc deficiency in the geriatric people: Serum zinc binding capacity

Background: Marginal zinc deficiency has been the matter of interest in recent years and investigations are concentrated on it. Subjects with insufficient zinc consumption diet demonstrate systemic symptoms as reduced appetite, growth retardation in preschool children; immune deficiency, dermatological problems, delayed wound healing in geriatric population. In marginal zinc deficiency, diagnostic laboratory criteria are in normal range. Objective: For this reason, it is difficult to diagnose marginal zinc deficiency. Argemi et al. [1988] proposed to measure serum zinc binding capacity in the determination of zinc status of pregnant women. It is possible to establish the quantity of zinc binding to serum protein as serum iron capacity. We used the same method to diagnose marginal zinc deficiency of risky geriatric people. Methods: In 43 subjects, 25 female and 18 male above 65 years of age, living in Seyran Baglari Nursing Home, we established serum zinc, serum zinc per gram of serum protein, serum zinc binding capacity, serum zinc binding capacity per gram of serum protein. We included 20 healthy adult subjects as control group. Among the 23 subjects with zinc deficiency, 15 subjects agreed to zinc supplementation. Elementary Zn (ZnSO 4 ) 30 mg/day was given for 90 days as zinc supplementation. All the parameters were repeated at the end of the second and the third months and 15 days after the medication was ceased. Results: In geriatric subjects, serum zinc and zinc per gram of serum protein were reduced; serum zinc binding capacity and zinc binding capacity per gram of serum protein were increased according to the control group. In 15 geriatric subjects supplemented with zinc preperation, serum zinc quantity demonstrated insignificant variation but serum zinc binding capacity was reduced significantly. Conclusion: In conclusion, serum zinc binding capacity seems to be an appropriate method for the diagnosis of marginal zinc deficiency.