Prevalence of vitamin D deficiency among pregnant women in Iran: A systematic review and meta-analysis

Vitamin D deficiency (VDD) has been considered as an undiagnosed pandemic. In recent review articles the relationship between VDD and several disorders of mothers and their newborns were indicated. The present study was aimed in order to investigate the VDD prevalence in Iranian pregnant women.
This First meta-analysis study was performed based on PRISMA checklist for systematic review and meta-analysis studies. A comprehensive literature searches of national and international databases including Scopus, PubMed, Science Direct, Cochrane, Web of Science, Magiran, Iranmedex, SID, Medlib and Google Scholar engine by using MESH keywords up to 2016 was empolyed.Two reviewers independently were conducted the search, including selection of studies, quality assessment and data extraction.
Eighteen studies and 5,572 pregnant women were included in the analysis. The prevalence of VDD in Iranian pregnant women with cut-off point of 10, 20 and 30ng/ml were calculated 41.9% (95%CI: 30.4-54.3), 68.6% (95%CI: 50.3-82.5) and 84.4% (95%CI: 74.2-91.1), respectively. The highest prevalence of VDD in trimester of pregnancy term in cutoff 10, 20 and 30 ng/ml was obtained in the second trimester (95% CI: 61.9 (61.95-36.7)), first trimester (95% CI: 89.4(87.8-90.8)) and third trimester (86.7(95% CI: 74.5-93.6)).
The prevalence of VDD in Iranian pregnant women is very high. Therefore, addressing VDD in women during pregnancy should be a health priority in Iran. To avoid of related disorders and adverse effects of VDD in mothers, appropriate interventions among pregnant women should be considered.