American Journal of Clinical Nutrition, Vol 28, 310-315, Copyright © 1975 by The American Society for Clinical Nutrition, Inc

ORIGINAL RESEARCH COMMUNICATIONS

Variability of creatinine excretion of normal, phenylketonuric and galactosemic children, and children treated with anticonvulsant drugs

JS Lewis, ML Bunker, SS Getts and R Essien

Creatinine per minute excretion rates in individual voidings varied as much as 300-500 percent of the 24-hour value for several children. Creatinine excretion rates were significantly more variable for children treated with anticonvulsant drugs than for normal children. Riboflavin-creatinine ratios determined on individual voidings were variable but adequate although total riboflavin was low. No time of day was found when creatinine excretion was representative of the 24-hour value. The creatinine height index when calculated from timed individual voidings during a 24-hour period varied for some children from 0.5 to more than 1.5 times published norms.