Randomized phase 2 trial of monthly vitamin D to prevent respiratory complications in children with sickle cell disease by Margaret T. Lee, Meyer Kattan, Ilene Fennoy, Stephen M. Arpadi, Rachel L. Miller, Serge Cremers, Donald J. McMahon, Jeri W. Nieves, and Gary M. Brittenham BloodAdv Volume 2(9):969-978 May 8, 2018 © 2018 by The American Society of Hematology

Margaret T. Lee et al. Blood Adv 2018;2:969-978 © 2018 by The American Society of Hematology

ViDAS trial schema. ViDAS trial schema. FENO, fractional exhaled NO; PFT, pulmonary function tests. Margaret T. Lee et al. Blood Adv 2018;2:969-978 © 2018 by The American Society of Hematology

ViDAS participant flow diagram. Margaret T. Lee et al. Blood Adv 2018;2:969-978 © 2018 by The American Society of Hematology

Annual rates of respiratory events by treatment group. Annual rates of respiratory events by treatment group. Data are shown in a Tukey box plot. The horizontal line in the box represents the median. The bottom and top of the box indicate the first and third quartiles; the upper whisker shows the largest value from the top of the box that is no further than 1.5 times the interquartile range (IQR), the lower whisker shows the smallest value from the bottom of the box to within 1.5 times the IQR, and data beyond the ends of the whiskers are displayed as points. The mean (♦; ± standard error of the mean [SEM]) annual rates of respiratory events at baseline, intervention year 1, and intervention year 2 were 3.91 ± 0.35, 3.34 ± 0.37, and 1.54 ± 0.37 and 4.34 ± 0.35, 4.28 ± 0.36, and 1.49 ± 0.37, respectively, for monthly standard-dose and high-dose oral vitamin D3. The rates did not differ significantly between the groups (P = .24), but they decreased significantly during year 2 in both groups (P = .0005). Margaret T. Lee et al. Blood Adv 2018;2:969-978 © 2018 by The American Society of Hematology

Mean serum 25-hydroxyvitamin D concentrations by treatment group. Mean serum 25-hydroxyvitamin D concentrations by treatment group. The mean serum 25-OHD concentrations of the groups receiving standard-dose (12 000 IU/mo) and high-dose (100 000 IU/mo) vitamin D3 did not differ statistically at baseline and rose to plateau at different levels at 3-4 months; overall mean concentration during the 2-year treatment period was significantly higher in the high-dose group (36.1 ng/mL) compared with the standard-dose group (19.1 ng/mL; P < .001). Error bars indicate SEM. Margaret T. Lee et al. Blood Adv 2018;2:969-978 © 2018 by The American Society of Hematology