Maternal 25(OH)D concentrations ≥40 ng/mL were associated with substantial reduction in preterm birth risk in a large, diverse population of women.
Link to Publication: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524288/
McDonnell SL, et al. Maternal 25(OH)D concentrations ≥40 ng/mL associated with 60% lower preterm birth risk among general obstetrical patients at an urban medical center. PLoS One. 2017;12(7):e0180483.