Zeinab Nazari - Department of Gynecology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
Javad Ghaffari - Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences.
Abbas Dabaghzadeh - Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences.
Negar Ghaffari - Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences.
Ali Reza Ranjbar - Institute of Interventional Allergology and Immunology, Cologne/Bonn, Germany.

Context: Asthma is a chronic inflammatory respiratory disorder, and nutritional conditions affect allergic diseases such as asthma. This study aims to find the relationship between maternal gestational vitamin D levels and asthma progression and wheezing in children later in life.  Objectives: Allergic disorders are common everywhere in the world. Asthma is the most chronic inflammatory respiratory disorder among children. It causes significant morbidity and mortality in children as well as adults. Vitamin D deficiency or insufficiency, is a global problem. Vitamin D has immunological effects, and it may prevent autoimmune diseases. Maternal plasma vitamin D during pregnancy has a different impact on children’s allergic disorders. Evidence Acquisition: This is a review article. We searched databases, including Google Scholar, PubMed, SID, IranDoc, Scopus, until now. The keywords for the search included maternal vitamin D, asthma, wheezing, children, and pediatric. We searched in the mentioned databases until March ۲۰۲۰. Full-text articles in the English language were included in this study. Results: A few articles were found in our search. All of them were cohort studies. They evaluated maternal vitamin D and its outcomes in their children’s asthma and wheezing using questionnaire data and serum samples. After assessing the articles (more than ۱۰۰), ۱۵ papers were included in our review. Six and four articles showed that higher maternal vitamin D levels reduce children’s asthma and or wheezing, respectively. In contrast, ۷ articles showed no association between maternal vitamin D and children’s asthma or wheezing. Vitamin D does not have any serious side effects. Because the articles were heterogenic, a meta-analysis could not be done. Conclusions: Administering vitamin D supplements or food enriched vitamin D during pregnancy has different effects on the prevalence of wheezing and or asthma in children.

Asthma, Children, Vitamin D, Pregnancy, Wheezing