: The growing interest in the new role of vitamin D, particularly as an immunomodulatory factor, has spurred basic research and the development of clinical trials to better understand the influence of supplementation on various diseases. Vitamin D is an important nutrient factor in human health due to its role in calcium metabolism regulation, cellular growth, differentiation and its fundamental discovered activity in immune functions. It has influenced different diseases, particularly inflammatory and autoimmune diseases, through immune response regulation, modulating innate and adaptive immunity. : The aim of this review was to explore the role of vitamin D in the main respiratory diseases in children such as asthma, chronic rhinosinusitis, cystic fibrosis and recurrent respiratory infections.