SummaryThe importance of diet and supplement intake in the onset and development of asthma has been advocated recently, and it may be important in the prevention and management of bronchial asthma. Long-chain n-3 polyunsaturated fatty acids (LCn3PUFAs), vitamins (Vit), choline, and probiotics may be candidates to reduce medication use and provide some protection from risk. Experimental studies of diet in bronchial asthma have demonstrated modification of pulmonary function and the immune system through mechanisms involving antioxidant effect, T-helper (Th) 2 and Th17 inhibition, tolerogenic regulatory T cell (Treg) function promotion, nuclear transcription factors and epigenetic regulation. Although studies in animal models have provided evidence of supportive effects of diet in asthma, there have been few longitudinal studies of dietary or supplement intake and asthma, and the available epidemiological data remain controversial and inconclusive.prevalence of asthma and allergy in their offspring [20]. Cord serum 25-Hydroxyvitamin D level was inversely associated with the risk of transient early wheezing by the age of 5 years, but no association was found with asthma [21]. Recent published data demonstrated that Vit D3 did not reduce the rate of first treatment failure or exacerbation in adults with persistent asthma and Vit D insufficiency, suggesting that therapeutic Vit D3 supplementation in patients with symptomatic asthma was not useful [22].