pubmed-article:7979170 | pubmed:abstractText | A study was conducted to investigate the relationship between vitamin C intake and the rate of tyrosine catabolism in premature babies. A 13C tyrosine breath test was developed for the measurement of tyrosine catabolism. Premature babies were randomly allocated to receive a daily intake of vitamin C which ranged from 8 to 100 mg/kg body weight, for 5 days. Tyrosine catabolism was measured at the beginning and the end of this period. Daily intakes of vitamin C of 20 mg/kg or more elicited a greater increase in tyrosine catabolism over 5 days than 8 mg/kg/day. The magnitude of the difference, in terms of percentage of tyrosine metabolised, was, however, small and of doubtful biological significance. Vitamin C intakes above 20 mg/kg/day had no further measurable effect on the catabolism of tyrosine. | lld:pubmed |