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. These 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. Both 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 FEV1 (p > 0.70) nor the overall average baseline specific airways conductance (p > 0.90). Additionally, no statistically significant difference (p > 0.60) was noted between log PD35SGaw vitamin C day and lactose day. Likewise, no statistically significant difference (p > 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.
ASJC Scopus subject areas
- Immunology and Allergy