a1 Department of Human Nutrition, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT
1. The results of a previously reported controlled trial of vitamin supplementation of elderly hospital patients, in which capillary resistance was measured by the Hess test, were examined and analysed statistically.
2. Capillary resistance was reduced during successive 3-monthly tests over a period of 12 months and the reduction was related to leucocyte ascorbic acid concentration.
3. It is postulated that the rate of recovery from capillary trauma inflicted by the test was dependent upon the function of ascorbic acid in the hydroxylation of proline to hydroxyproline during collagen synthesis.
(Received August 02 1971)
(Accepted November 26 1971)