Dietary recommendations and r and omized trials on vitamin D supplementation should evaluate whether increases in circulating 25-hydroxyvitamin D levels match expectations -- for instance , the average increases obtained by trials on vitamin D3 without concomitant calcium supplements
CONTEXT Few studies in subjects over 50 yr of age have evaluated the influence of variable doses of vitamin D supplementation on serum 25-hydroxyvitamin D levels .
OBJECTIVE We performed a meta- analysis of changes in circulating 25-hydroxyvitamin D level associated with vitamin D supplementation in Caucasian subjects over 50 yr old .
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
Dietary recommendations and r and omized trials on vitamin D supplementation should evaluate whether increases in circulating 25-hydroxyvitamin D levels match expectations -- for instance , the average increases obtained by trials on vitamin D3 without concomitant calcium supplements
CONTEXT Few studies in subjects over 50 yr of age have evaluated the influence of variable doses of vitamin D supplementation on serum 25-hydroxyvitamin D levels .
OBJECTIVE We performed a meta- analysis of changes in circulating 25-hydroxyvitamin D level associated with vitamin D supplementation in Caucasian subjects over 50 yr old .