[The zinc status in a selected Spanish population. A multivariate analysis]

There are no previous studies on the zinc status in the healthy, adult, Spanish population. The objective of this study was to obtain the levels of zinc in the serum and hair of this population to determine the normal nutritional status of zinc, and evaluating the influence of certain factors like age, sex, type of residence, body mass index (BMI) hair color, or recent food intake (zinc and fiber contents of the diet) on this status. Using a simple randomized sampling, 186 blood donors of both sexes with ages comprised between 18 and 65 years, were selected. The results were analyzed using uni- and multi-variate statistical techniques. The average concentration of zinc in serum was 97.22 micrograms/dl (95% CI: 95.1-99.4); the average zinc level in hair was 163.86 micrograms/g (95% CI: 157.8-169.9). The serum zinc was individually associated with the type of residence and the zinc and fiber contents of the diet. The zinc in hair was associated with sex, age, body mass index, and hair color. Using a multivariate analysis, predictive models of multiple regression were obtained for the serum zinc: y = 109.69 - 1.39 (dietary zinc) - 4.63 (sex) - 0.65 (dietary fiber), for the zinc in the serum, and y = 199.34 + 26.62 (sex) - 2.08 (BMI) - 0.47 (age) for the zinc in the hair. The serum concentration decreases as the dietary zinc and fiber decreases and women have lower levels. The zinc in hair is increased in women and is reduced with increasing age and BMI.