HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Duff, T. L. Articles by Whiting, S. J. Search for Related Content PubMed PubMed Citation Articles by Duff, T. L. Articles by Whiting, S. J.

Calciuric Effects of Short-Term Dietary Loading of Protein, Sodium Chloride and Potassium Citrate in Prepubescent Girls

College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, CANADA

Address reprint requests to: Susan J. Whiting, PhD, College of Pharmacy and Nutrition, 110 Science Place, University of Saskatchewan, Saskatoon, SK, CANADA S7N 5C9

Objective: Studies using adult human subjects indicate that dietary protein and sodium chloride have negative effects on the retention of calcium by increasing urinary calcium excretion, while alkaline potassium improves calcium retention along with decreasing urinary calcium losses. This study investigated the effect of these dietary factors on acute urinary calcium excretion in 14 prepubescent girls age 6.7 to 10.0 years.

Methods: Subjects provided a fasting urine sample then consumed a meal containing one of five treatments: moderate protein (MP) providing 11.8 g protein, moderate protein plus 26 mmol sodium chloride (MP+Na), high protein (HP) providing 28.8 g protein, high protein plus 26 mmol sodium chloride (HP+Na), or high protein plus 32 mmol potassium as tripotassium citrate (HP+K). Urine was collected at 1.5 and 3.0 hours after the meal. Supplemental protein was given as 80:20 casein:lactalbumin. Test meals were isocaloric, and unless intentionally altered, components of interest except phosphate were equal between treatments. Each subject completed all five treatments.

Results: Urinary calcium excretion rose after the meal, peaking at 1.5 hours. There were no significant differences in calcium excretion between treatments at any time point. The high protein treatments did not result in a significant increase in either net acid or sulfate excretion at 1.5 hours compared to moderate protein. Dietary sodium chloride had no effect on urinary sodium or calcium excretion over the 3 hours. After the potassium treatment, sodium excretion increased (p0.002) and net acid excretion decreased (p<0.001) compared to other treatments at 1.5 hours.

Conclusions: In children, a simultaneous increase in protein and phosphorus due to increased milk protein intake did not increase acute urinary calcium excretion. An effect of dietary sodium chloride on acute urinary calcium excretion was not observed. Both these findings were similar to those of adult studies previously conducted in the same laboratory using similar format and treatments. Potassium citrate was not hypocalciuric in children, a response differing from that for adults, who have shown a decrease in acute urinary calcium excretion in response to alkaline potassium treatment. Further characterization of calciuric responses to dietary factors is required for children, who may differ from adults in many respects.

Key words: calcium, urine, children, potassium, sodium, milk protein

This article has been cited by other articles:

				G. Jones, M. D Riley, and S. Whiting Association between urinary potassium, urinary sodium, current diet, and bone density in prepubertal children Am. J. Clinical Nutrition, April 1, 2001; 73(4): 839 - 844. [Abstract] [Full Text] [PDF]

				A. Maggioni Nutrition and Physical Activity with Particular Emphasis on Bone Health J. Am. Coll. Nutr., April 1, 1998; 17(2): 103 - 104. [Full Text] [PDF]