Effect of ascorbic acid on urinary hydroxyproline of children receiving corticosteroids.

Oral administration of ascorbic acid, 0·5 g every 8 hours for a period of 4 days, had no effect on the urinary hydroxyproline excretion of 7 healthy children aged 8 to 14 years. When the same medication was given to 8 children aged 9 to 14 years who were receiving large doses of prednisolone (2 mg/kg per 24 hr) for a period of at least 15 days before as well as during ascorbic acid administration, a rise in the urinary hydroxyproline excretion was observed (from a mean value of 44±4·1 SE before to 67±4·6 mg/24 hr on the 4th day of ascorbic acid administration, P <0·001). Urinary hydroxyproline excretion of 3 children 4 days after stopping ascorbic acid administration, while still on prednisolone, had returned to the level observed before ascorbic acid. It is concluded that large doses of ascorbic acid can, under acute conditions, neutralize the inhibitory action of corticosteroids on new collagen formation.