Inclusion of 95 % range in the model to account for inter-individual variability increased the predicted intake of vitamin D needed to maintain serum 25(OH)D ≥ 50 nmol/l to 930 IU/d .
Efficacy of different doses and time intervals of oral vitamin D supplementation with or without calcium in elderly nursing home residents
Summary The effect of equivalent oral doses of vitamin D3 600 IU/day , 4200 IU/week and 18,000 IU/month on vitamin D status was compared in a r and omized clinical trial in nursing home residents . A daily dose was more effective than a weekly dose , and a monthly dose was the least effective . Introduction It is assumed that equivalent daily , weekly or monthly doses of vitamin D3 equally influence vitamin D status . This was investigated in a r and omized clinical trial in nursing home residents . Methods The study was performed in ten nursing homes including 338 subjects ( 76 male and 262 female ) , with a mean age of 84 ( ± SD 6.3 years ) . They received oral vitamin D3 either 600 IU/day , or 4200 IU/week , or 18,000 IU/month or placebo . After 4 months , calcium was added during 2 weeks , 320 mg/day or 640 mg/day or placebo . Outcome : serum levels of 25-hydroxyvitamin D ( 25(OH)D ) , parathyroid hormone ( PTH ) and bone turnover markers . Statistical approach : linear multilevel analysis . Results At baseline , mean serum 25(OH)D was 25.0 nmol/L ( SD 10.9 ) , and in 98 % , it was lower than 50 nmol/L. After 4 months , mean serum 25(OH)D levels increased to 62.5 nmol/L ( after daily vitamin D3 69.9 nmol/L , weekly 67.2 nmol/L and monthly 53.1 nmol/L , P < 0.001 between groups ) . Median serum PTH levels decreased by 23 % ( p < 0.001 ) . Bone turnover markers did not decrease . Calcium supplementation had no effect on serum PTH and bone turnover . Conclusion Daily vitamin D was more effective than weekly , and monthly administration was the least effective
Inclusion of 95 % range in the model to account for inter-individual variability increased the predicted intake of vitamin D needed to maintain serum 25(OH)D ≥ 50 nmol/l to 930 IU/d .