Litonjua, Augusto A., Nancy E. Lange, Vincent J. Carey, Stacey Brown, Nancy Laranjo, Benjamin J. Harshfield, George T. O’Connor, et al. 2014. The Vitamin D Antenatal Asthma Reduction Trial (VDAART): Rationale, design, and methods of a randomized, controlled trial of vitamin D supplementation in pregnancy for the primary prevention of asthma and allergies in children. Contemporary Clinical Trials 38, no. 1: 37–50. doi:10.1016/j.cct.2014.02.006.