Mean ( s.d. ) serum-25 ( OH ) D increased in all groups ( time effect , P < 0.001 ) and differed between groups ( time dosage interaction , P < 0.001 ; 50,000 IU : from 44.016.0 to 70.015.0 nmol/l ; 100,000 IU : 48.011.0 to 82.017.0 nmol/l ; placebo : 45.018.0 to 54.018.0 nmol/l ) .