Overall , intervention groups obtained higher 25(OH)D concentration than controls and there was obvious dose – response effect between intake dose and 25(OH)D concentration .
Baseline 25(OH)D concentration and age were significant indicators for 25(OH)D concentration .
Conclusions Regional- and age-specific recommended dosages of VitD supplements for population to achieve optimal 25(OH)D concentrations have been suggested
Background / Objectives Optimal doses of vitamin D ( VitD ) supplement in different population s are unclear .
We aim to evaluate the relationship between VitD supplementation and post-intervention serum 25-hydroxyvitamin D [ 25(OH)D ] concentration , to provide a recommended dosage of VitD for achieving an optimal 25(OH)D concentration for different population s .
Effect of Vitamin D3 Supplementation in Black and in White Children: A Randomized, Placebo-Controlled Trial.
CONTEXT Dosages of vitamin D necessary to prevent or treat vitamin D deficiency in children remain to be clarified . OBJECTIVE To determine the effects of vitamin D3 1000 IU/d on serum 25-hydroxyvitamin D [ 25(OH)D ] , PTH , and markers of bone turnover ( osteocalcin and collagen type 1 cross-linked C-telopeptide ) in black children and white children , and to explore whether there is a threshold level of 25(OH)D associated with maximal suppression of serum PTH concentration . DESIGN Healthy 8- to 14-year-old Pittsburgh-area black ( n = 84 ) and white ( n = 73 ) children not receiving vitamin supplements , enrolled from October through March from 2008 through 2011 , were r and omized to vitamin D3 1000 IU or placebo daily for 6 months . RESULTS The mean baseline concentration of 25(OH)D was < 20 ng/mL in both the vitamin D-supplemented group and the placebo group ( 19.8 ± 7.6 and 18.8 ± 6.9 ng/mL , respectively ) . The mean concentration was higher in the supplemented group than in the placebo group at 2 months ( 26.4 ± 8.1 vs 18.9 ± 8.1 ng/mL ; P < .0001 ) and also at 6 months ( 26.7 ± 7.6 vs 22.4 ± 7.3 ; P = .003 ) , after adjusting for baseline 25(OH)D , race , gender , pubertal status , dietary vitamin D intake , body mass index , and sunlight exposure . Increases were only significant in black children , when examined by race . The association between 25(OH)D and PTH concentrations was inverse and linear , without evidence of a plateau . Overall , vitamin D supplementation had no effect on PTH and bone turnover  . CONCLUSIONS Vitamin D3 supplementation with 1000 IU/d in children with mean baseline 25(OH)D concentration < 20 ng/mL effectively raised their mean 25(OH)D concentration to ≥20 ng/mL but failed to reach 30 ng/mL.  Vitamin D supplementation had no effect on PTH concentrations
Overall , intervention groups obtained higher 25(OH)D concentration than controls and there was obvious dose – response effect between intake dose and 25(OH)D concentration .
Baseline 25(OH)D concentration and age were significant indicators for 25(OH)D concentration .
Conclusions Regional- and age-specific recommended dosages of VitD supplements for population to achieve optimal 25(OH)D concentrations have been suggested
Background / Objectives Optimal doses of vitamin D ( VitD ) supplement in different population s are unclear .
We aim to evaluate the relationship between VitD supplementation and post-intervention serum 25-hydroxyvitamin D [ 25(OH)D ] concentration , to provide a recommended dosage of VitD for achieving an optimal 25(OH)D concentration for different population s .