Statistical analysis
Sample size was derived from the primary objective, based on results of our previous study showing that the average serum 25(OH)D levels were 50 nmol/L at baseline and increased to 72 nmol/L at day 100 post-aHSCT [Our analysis followed a modified intention-to-treat principle. Participants who died or relapsed between the time of randomization and day 100 post-aHSCT were excluded from the analysis as these participants lacked day 100 25(OH)D results. We did not use statistical techniques to impute missing data (eg, by multiple imputation), because we judged that the missing data were scarcity (eg. less than 5%).Two sample 