Citrate is excreted in comparatively large amounts in human urine, and its excretion varies with age, diet, sex, and other factors from 100 to 1500 mg. per day.1-4 It is lower in infants and children as compared with adults.1-3,5-7 Citrate excretion is decreased by acidosis7-12 (dietary, uremic, and diabetic) and by testosterone administration.13 It is increased in alkalosis7-12 and by the administration of estrogens,14,15 parathyroid extract,2,16,17 and vitamin D.18-22
Previous experimental and clinical studies have suggested that urinary citrate aids in the chelation of calcium into a soluble complex. Low citrate levels in the presence of normal calcium-phosphorous ratios may play a role in the formation of renal calculi.2,23,24 In addition, citrate therapy has been reported to have induced an apparent improvement in a case of nephrocalcinosis.25
In rats, acetazolamide administration has been observed to result in the deposition of calcium