The aim of the present study was to define referential values of 5 basic bioelements (Ca, Mg, Zn, Cu, Fe) and 2 toxic metals (Pb and Cd) in the hair of Polish adults aged 20 to 40 years, based on the research conducted from 1991 to 2006 on a group of 5733 formally healthy subjects of both sexes. The results of our biochemical tests were subjected to statistical analysis and they can be treated as referential norms for the concentrations of analyzed bioelements in the hair of the Polish population. Our analyses confirm significant differences in accumulations of certain elements in women's and men's hair. We established that women's hair Ca, Mg, Zn (p = 0.000000) and hair Cu (p = 0.0001) concentrations are higher than they are in men. A lower mean of hair Fe concentrations in women were confirmed by some tests. Men have significantly higher (p = 0.0000) concentrations of toxic metals (hair Pb and Cd), which keep increasing with age. Analyses of correlations confirm significance (for the assumed level of significance alpha = 0.05) of synergistic interactions between bioelements: Ca-Mg (r = +0.70), Ca-Zn (r = +0.39), Ca-Cu (r = +0.14), Mg-Zn (r = +0.31), Mg-Cu (r = +0.10), Zn-Cu (r = +0.11), Zn-Fe (r = +0.07). Significance (a < 0.05) of antagonistic interactions with toxic metals: Ca-Pb (r = -0.13), Zn-Pb (r = -0.15), Mg-Pb (r = -0.15), Zn-Cd (r =-0.02) was confirmed. Significance (alpha < 0.05) of synergistic effects with toxic metals: Pb-Cd (r = +0.35), Fe-Pb (r = +0.16), Fe-Cd (r = +0.08) was also confirmed. Adults in whose hair bioelements and hair toxic metals concentrations have shown values outlying from reference and who have too many toxic elements and too few bioelements should undergo further diagnostic tests since the results could be a sign of disturbances that could lead to various diseases.