Maternal Vitamin D Status and Development of Asthma and Allergy in Early Childhood.

Vitamin D has an indisputable immunodulatory role in both lung and immune system development, which is initiated during fetal life and is mainly accomplished in the first years of extrauterine life. Several published studies have shown that low levels of vitamin D may increase the risk of developing asthma and allergic diseases. Moreover, vitamin D deficiency epidemic reported over the last decades coincides with an increase in the prevalence of asthma and allergies in westernized societies. Since placental transfer of 25(OH)D is the major source of vitamin D in the developing fetus, important questions concerning the impact of maternal vitamin D status on the outcome of pregnancy have arisen. The aim of this review is to present the current evidence regarding the determinants of vitamin D status in pregnancy as well as its role in the development of asthma and allergies in early childhood.