A. Analyses based on levels. Secondary analyses using baseline and follow-up maternal 25OHD levels will be performed. We will investigate the effect of baseline and follow-up maternal levels separately on the development of primary and secondary outcomes in the trial. Additionally, we will categorize mothers into categories based on joint baseline and follow-up levels. Mothers who have baseline levels and follow-up levels ≥ 40 mg/dl will be categorized in the HI-HI group; those who have baseline levels and follow-up levels < 40 mg/dl will be categorized in the LO-LO group; mothers who do not meet these definitions will be categorized either in the HI-LO or LO-HI groups based on their baseline and follow-up levels.