Is Vitamin D Status Associated with Depression, Anxiety and Sleep Quality in Pregnancy: A Systematic Review

BACKGROUND: Women's mental health is a significant health issue for pregnant women during and after pregnancy. Postpartum depression (PPD) is defined as the presence of depression in the 1(st) year after delivery. This study reviews the relationship between Vitamin D levels, anxiety and poor sleep quality related to pregnancy. MATERIALS AND METHODS: A systematic search was conducted on documents presented in PubMed, Scopus, ProQuest, Science Direct, Google Scholar and Web of Science databases until March 2020. Three separate search paths were considered for three different disorders with particular keywords. All observational studies that investigate the relationship between Vitamin D levels and PPD, sleep disorders, and anxiety were selected for inclusion in the study. RESULTS: Search yielded 14 eligible studies. Quality of most included studies was medium to high. Nine studies reported that Vitamin D deficiency was directly associated to the incidence of PPD and sleep disorders. One study reported an indirect association, and three researches did not observe any association between Vitamin D status, sleep disorders and PPD. One study reported a direct association to anxiety but did not have any relation to PPD. CONCLUSIONS: PPD and sleep quality during pregnancy associated to Vitamin D deficiency directly. Although studies have several limitations, the importance of sufficient Vitamin D status in pregnant women has been addressed in all studies, especially regarding the prevention of PPD, anxiety, and poor sleep quality during the pregnancy.