Health problems and vitamin C in Canadian northern military operations

As part of a continuing study of health problems pertinent to Canadian Northern Military operations, two aspects of Vitamin C have been examined in land element personnel participating on Northern Winter Exercises. This report describes results of an ongoing Vitamin C survey designed to examine both the Vitamin C status of troops and the effects of a daily Vitamin C supplement on the incidence and severity of colds in troops undergoing operational training. Results indicate that a daily 1000 mg supplement of Vitamin C reduced significantly the incidence of colds as assessed on the basis of symptom complexes reported on health survey cards. While the overall incidence of colds was influenced significantly by Vitamin C, both on an individual and a tent group basis, the duration of local cold symptoms was not. In those individuals who contracted a cold, nasal and throat and chest symptoms were observed to persist for similar periods of time in both placebo and Vitamin C supplemented groups. The Vitamin C group, however, did show a significant reduction in the duration of the more constitutional symptoms related to a general feeling of "well-being". The Vitamin C status of individuals was assessed on the basis of whole blood ascorbate levels determined before and after participation on Northern exercises. A significant reduction of whole blood ascorbate was observed postexercise on three separate serials of Exercise New Viking, the troops of which were supplied with RP-4 field rations. In view of the fact that only a minor reduction of whole blood ascorbate was observed on anotherserial, the troops of which were supplied with IRP field rations, it is not possible to determine whether the reduction in ascorbate status was a reflection of altered dietary intake or an increased requirement for Vitamin C under the activity and exposure conditions experienced on Northern operations. Further work is required to clarify this situation.