Effects of ascorbic acid on pulmonary functions in mild asthma.

Twenty subjects with mild asthma took a short course of moderately high doses of Vitamin C (500 mg four times daily for 3 days and 1 g prior to spirometric evaluation). There were no differences in pulmonary functions just prior to and after therapy. There were no adverse reactions noted. If, as reported, Vitamin C has a beneficial effect in asthma, it does not appear to be due to a bronchodilatory effect.