NOTTINGHAM, England--Vitamin E supplementation may be ineffective in reducing the incidence of ozone-induced bronchoconstriction, according to a study published in the August issue of Thorax (59, 8: 652-656, 2004) (http://thorax.bmjjournals.com).
Researchers from the University of Nottingham randomized 72 adults from a clinical trial register to receive 500 mg natural vitamin E or matched placebo for six weeks in a placebo-controlled, double blind, parallel group clinical trial. Test subjects were between 18 and 60 years, received a regular “maintenance treatment” of at least one dose of inhaled corticosteroid per day, tested positive in a skin prick test to one of three common allergens, and displayed bronchial hyperresponsiveness to methacholine challenge (a test to determine the presence or severity of asthma performed by inhaling the drug in increasing doses in an attempt to produce a change in pulmonary function). Test subjects were monitored for forced expiratory volume, forced vital capacity, mean morning and evening peak flow, symptom scores, bronchodilator use, and serum immunoglobulin E levels.
No significant difference in outcomes was found between the vitamin E and placebo groups. Vitamin E supplementation had no effect on any measure of asthma control, either in the intention to treat or per protocol analysis. Vitamin E supplementation also had no effect on serum immunoglobulin levels.
The researchers concluded dietary supplementation with vitamin E adds no benefit to current standard treatment in adults with mild to moderate asthma.