1000 mg of aluminum day thus these women were fed a diet low in magnesium for the full 48 days the other five women were fed 1 the boron basal diet supplemented with 200 mg of magnesium day and 2 the boron basal diet supplemented with 200 mg of magnesium and 1000 mg of aluminum day all urine excreted daily was collected with care each morning at 8 00 a m urine was collected in plastic containers containing 6 ml of 3 m hydrochloric acid urinary calcium and magnesium were determined by using standard atomic absorption methodology urinary phosphorus was determined by using the method of fiske and subbarow j biol chem 66 375 400 1925 urine samples from the last 20 days of each 24 day dietary period were used to obtain the means given in tables i and ii blood was drawn using standard phlebotomy techniques between 6 00 and 7 00 a m after 10 hr of fasting serum was obtained on days 16 and 24 in each 24 day dietary period for the radioimmunoassay determination of 17 u03b2 estradiol and testosterone the standard kits used for analyses radioassay system laboratories carson ca detected the total unconjugated form of testosterone and 17 u03b2 estradiol the test for 17 u03b2 estradiol did not distinguish between the free and protein bound states of this most biologically active form of naturally produced human estrogen it is understood that the foregoing detailed description is given merely by way of illustration and that modifications and variations may be made therein without departing from the spirit and scope of the invention table i__________________________________________________________________________effect in postmenopausal women of boron and aluminumon urinary excretion of calcium magnesium and phosphorusdietary treatment urinary excretion g 24 hrmg day low mg diet sup a adequate mg diet sup.