Conclusions
PRETERM BIRTH
In conclusion, in women with a baseline 25(OH)D 25-100 nmol/l, 1000 IU/day cholecalciferol during pregnancy did not reduce the incidence of preterm birth but was associated with a modest increase in the proportion who achieved a SVD and reduction in instrumental deliveries. Further trials are required to confirm this finding, and in particular, including women with very low levels of 25(OH)D at baseline.