Vitamin C as a preventive medicine against common colds in children.

During 7 weeks in the spring of 1973 a double-blind pilot study on 172 children in the age group 8-9 was carried out to test the possible effect of 1000 mg vitamin C daily as a prophylactic agent against common colds. During the autumn of 1973, a main study was carried out on 642 children of the same age. The investigations had the same pattern and lasted for 3 months. Both studies have been processed on the same principles. The results were somewhat divergent but, like previously published studies on children, seemed to indicate that the duration and severity of the cold were reduced while, on the other hand, the incidence remained unaltered or indeed increased. The total number of days of upper respiratory tract infection was smaller for the vitamin C group only in the pilot study (not in the main study). No proven biochemical effects were obtained. Preventive treatment of healthy children with vitamin C in large doses this had no definitely proved effect against colds.