Effects of Soy Isoflavones Supplementation and Exercise on Urinary Calcium, Magnecium, Copper and Zinc Excretion in Postmenopausal Women

ABSTRACT

This study assessed the effects of soy isoflavones supplementation with exercise on urinary mineral (calcium, magnesium, copper, zinc) excretion as an index of bone resorption rates in 67 postmenopausal women. A total subjects were assigned to Isoflavone (90 mg/day) or placebo groups. These groups were further divided into groups that undergone a regular exercise or a rather sedentary state performing daily activity only. We conducted study eight week period. Result showed urinary zinc excretion was more significantly decreased in the isoflavone-sedentary group (-180.76 +/- 171.30 ug/day) than in the placebo-sedentary group (-31.23 +/- 146.60 ug/day), placebo-exercise group (40.93 +/- 193.44 ug/day) and isoflavione-exercise group (-1.21 +/- 160.61 ug/day) (p < 0.05), but no significant changes in the differences between the values of the pre and post study values in urinary calcium, magnesium and copper excretion. These results suggest that Isoflavone supplementation decrease urinary zinc excretion rate in postmenopausal subjects.