Relative importance of urinary sulfate and net acid excretion as determinants of calciuria in normal subjects
Puche, R.C.; Feldman, S.
Medicina 52(3): 220-224
1992
ISSN/ISBN: 0025-7680 PMID: 1342687 Document Number: 391166
Healthy subjects (8 women, 7 men; 23 to 56 years old) who consumed a mixed western-type diet (animal protein 70 to 150 g/day) and vegetarian subjects (7 women, 4 men; 20 to 24 years old) who consumed protein 80 to 90 g/day were studied. Urine was sampled after fasting and a full lunch. Calcium intake of all subjects was from 350 to 450 mg/day. Urine was collected from omnivorous subjects after being given ammonium chloride 0.9 or methionine 0.7 mmol/kg during fasting. During fasting a 39.6% variance in Ca in urine of omnivorous subjects was accounted for by net acid excretion and 4% by sulfate in urine. After the meal, net acid accounted for 6.9% and sulfate in urine for 11.8% of variance in Ca in urine. After ammonium chloride, net acid excretion exceeded the importance of sulfaturia (36.2 vs. 8.4%); the opposite was true with methionine (1.5 and 46.2%). Excretion of the 3 variables was reduced in the vegetarians when compared with omnivores. During fasting, variance of Ca in urine was accounted for mainly by net acid excretion (85.7%). After the meal, net acid (4.9%) and sulfate (2.2%) were less important as independent determinants of Ca in urine.