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 .
Vitamin D2 dose required to rapidly increase 25OHD levels in osteoporotic women
Objective : Assessment of the effectiveness and safety of high daily 125 μg ( 5000 IU ) or 250 μg ( 10 000IU ) doses of vitamin D2 during 3 months , in rapidly obtaining adequate 25 hydroxyvitamin D ( 25OHD ) levels . Design : Longitudinal study .Subjects : Postmenopausal osteopenic/osteoporotic women ( n=38 ) were studied during winter and spring . Median age ( 25–75th percentile ) was 61.5 ( 57.00–66.25 ) years , and mean bone mineral density ( BMD ) was 0.902 (0.800–1.042)g/cm2 . Subjects were r and omly divided into three groups : control group ( n=13 ) : no vitamin D2 , 125 μg/day ( n=13 ) and 250 μg/day ( n=12 ) of vitamin D2 groups , all receiving 500 mg calcium/day . Serum calcium , phosphate , bone alkaline phosphatase ( BAP ) , C-telopeptide ( CTX ) , 25OHD , mid-molecule parathyroid hormone ( mmPTH ) , daily urinary calcium and creatinine excretion were determined at baseline and monthly . Results : For all subjects ( n=38 ) , the median baseline 25 hydroxyvitamin D ( 25OHD ) level was 36.25 ( 27.5–48.12 ) nmol/l . After 3 months , 8 % of the patients in the control group , 50 % in the 125 μg/day group and 75 % in the 250 μg/day group had 25OHD values above 85 nmol/l ( 34 ng/ml ) . Considering both vitamin D2 groups together , mmPTH and BAP levels diminished significantly after 3 months ( P<0.02 ) , unlike those of CTX . Serum calcium remained within normal range during the follow-up . Conclusions : The oral dose of vitamin D2 required to rapidly achieve adequate levels of 25OHD is seemingly much higher than the usual recommended vitamin D3 dose ( 20 μg/day ) . During 3 months , 250 μg/day of vitamin D2 most effectively raised 25OHD levels to 85 nmol/l in 75 % of the postmenopausal osteopenic/osteoporotic women treated
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 .