Pregnant women should take 4,000 IU vitamin D daily recommend researchers after publishing their study.

494 pregnant women were given a daily dose of vitamin D (400, 2000 or 4000 IU) from 12-16 weeks’ gestation until delivery to evaluate the effects of vitamin D during pregnancy. Women who took the highest vitamin D dosage had the lowest rates of preterm labour and preterm birth, and the lowest rates of infection. No adverse events related to vitamin D were reported for mothers or babies with any of the doses tested.

Recent studies have shown that vitamin D deficiency during pregnancy is a serious public health issue and this study found that not only was taking vitamin D supplements during pregnancy safe for mother and baby, but also that it can prevent preterm labour/births and infections.

http://www.sciencedaily.com/releases/2010/05/100501013417.htm