CONCLUSIONS: None of the preterm infants in this study had normal vitamin D level, which underlined the burden of vitamin D deficiency in pregnant women and their offspring. RDS was more common in severely vitamin D-deficient preterms. Determination of vitamin D status of the mothers and appropriate supplementation might be a valuable strategy to reduce RDS, in addition to antenatal steroids. Besides, since vitamin D is a regulatory factor in many organs during fetal development, long-term effects of in utero vitamin D deficiency warrant further studies. PMID: 25008013 [PubMed - indexed for MEDLINE] (Source: International Journal for Vitamin and Nutrition Research)