Effects of complementary and excess diet supplementation with selected minerals on their metabolism and distribution in the body: a model study.

BACKGROUND

n. The study was aimed at determining, on an animal model, effects of supplementing a diet, modified by substituting whole wheat and corn grains with white flour and sucrose, with calcium, magnesium, zinc, and chromium on metabolism of the minerals and their distribution in the body.

METHODS

The study involved 4 groups of Wistar rat females (n = 11) fed: a standard feed (group I) containing, i.a., whole wheat and corn grains; modified feed (84% and 50% of whole wheat and corn grains, respectively, in the standard feed substituted with Type 500 wheat flour and sucrose, respectively) (group II); modified feed with complementary supplementation (elimination of Ca, Mg, Zn, and Cr deficiencies resulting from diet modification) (group III); and modified feed with excess supplementation (the same minerals applied in excess, i.e., amounts from 0.5 to 3 times higher than the deficiencies produced by diet modification) (group IV). The replacement of whole grains with white flour and sucrose, as well as the mineral  supplementation could, to some extent, imitate the contemporary eating habits and supplementation applied in food technology. The excess supplementation is, on the other hand, typical of current behaviours of various social groups.

RESULTS

Both types of supplementation resulted in a significant increase in the perivisceral adipose tissue content, but did not affect the fat tissue content in muscles. The supplementation applied did not change the content of calcium, magnesium, and zinc in muscles, nor did it significantly change calcium and magnesium excretion with urine. However, changes in the ALP activity and calcitonin concentration did not suggest the deposition of the minerals in bones.

CONCLUSIONS

Analysis of the results allowed to conclude that: 1) except for chromium, contents of the selected minerals in the tissues examined and urea, as well as concentrations of calcitonin and alkaline phosphatase (ALP) activities did not point to any significant effect of the supplementation applied on the body contents of those minerals; 2) effects observed as the accumulation of perivisceral, epicardial and intramuscular adipose tissue, as well as increased body weight increments could have been related to disturbed proportions of the minerals supplemented, their synergy and antagonism and, consequently, a potential generation of secondary deficiencies and excesses which could significantly affect individual metabolic pathways; 3) the intensity of changes observed was generally higher in the females receiving complementary supplementation, although their uptake of minerals studied was similar to that shown by the females kept on the standard diet.