Table 4

Biochemical outcomes by allocation

Active (2 months: n=131; 12 months: n=118)Control (2 months: n=97; 12 months: n=86)Adjusted mean difference (95% CI)*p for allocation-time interactionp for individual time point†
Mean trough serum 25(OH)D, nmol/L (SD)
 2 months65.5 (19.8)52.9 (21.7)13.2 (8.3 to 18.0)<0.001<0.001
 12 months85.3 (24.3)59.1 (26.0)25.7 (20.6 to 30.7)<0.001
Mean serum corrected calcium, mmol/L (SD)
 2 months2.40 (0.09)2.40 (0.09)0.00 (–0.02 to 0.02)0.21
 12 months2.43 (0.13)2.41 (0.07)0.02 (0.00 to 0.04)
  • *Adjusted for study group (resident vs carer) and minimisation variables (level of care, size of scheme and season of randomisation).

  • †p for individual time point only presented where p for allocation-time interaction <0.05.

  • 25(OH)D, 25-hydroxyvitamin D.