American Journal of Clinical Nutrition, Vol 26, 1207-1211, Copyright © 1973 by The American Society for Clinical Nutrition, Inc.

Studies of bladder stone disease in Thailand. XVI. Effect of 4-hydroxy-l-proline and orthophosphate supplementations on urinary composition and crystalluria

¹ From the Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Bangkok, Thailand and Department of Food and Nutritional Sciences, University of Hawaii, Honolulu, Hawaii 96822

The present work was conducted to determine the effect of oral hydroxy-l-proline supplements on oxalcrystalluria and urine composition in male infants. The subjects ranged in age from 6 to 12 months and lived in villages of Ubol Province, Thailand, where bladder stone disease is common. The study was divided into four periods as follows: control (5 days), 4-hydroxy-l-proline supplementation at 1 g/day (10 days), phosphate buffer supplementation at approximately 500 mg P/day (7 days), and 4-hydroxy-l-proline supplementation at 1 g/day (7 days). During the entire study, the infants received their usual diet of breast milk, premasticated glutinous rice, and water. Oxalcrystalluria and an occasional clumping of crystals were observed during the control period. Hydroxyproline supplements exacerbated the condition, whereas the administration of phosphate markedly reduced the crystalluria and eliminated the clumping. Urinary oxalate and hydroxyproline excretion values were increased over the control period by the hydroxyproline supplement. The administration of phosphate brought about an increase in the excretion of phosphate, but a decrease in the excretion of calcium and oxalate compared with the previous period. The readministration of hydroxyproline resulted in the same changes as seen during its first administration. It is suggested that a relationship exists among urinary hydroxyproline, calcium, and oxalate with oxalate crystalluria and crystal clumping.