The effect of vitamin C on antigen-induced bronchospasm.

The effect of vitamin C pretreatment in preventing ragweed-induced bronchospasm was evaluated in 6 ragweed-sensitive asthmatics studied in a double-blind randomized fashion. The patients received either lactose capsules or 500 mg of ascorbic acid and were studied out of season. Antigen dose-response curves were determined prior to the administration of lactose or ascorbic acid in each individual subject and subsequently after administration of ascorbic acid or lactose. Bothe PD20FEV1 (provocation dose necessary for a 20% reduction in forced expiratory volume in 1 second) and PD35SGaw (provocation dose necessary for a 35% reduction in specific airways conductance) were determined. In none of the six patients was there a change in baseline FEV 1 (p greater than 0.70) nor the overall average baseline specific airways conductance (rho greater than 0.90). Additionally, no statistically significant difference (p greater than 0.60) was noted between log PD35SGaw vitamin C day and lactose day. Likewise, no statistically significant difference (p greater than 0.60) was evident when comparing log PD20FEV1 lactose and ascorbic acid days. Vitamin C (500 MG) HAS NO PROTECTIVE EFFECT AGAINST RAGWEED ANTIGEN-INDUCED BRONCHOSPASM.