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 .
Vitamin D intake to attain a desired serum 25-hydroxyvitamin D concentration.
BACKGROUND Indirect evidence suggests that optimal vitamin D status is achieved with a serum 25-hydroxyvitamin D [ 25(OH)D ] concentration > 75 nmol/L. OBJECTIVE We aim ed to determine the intake of vitamin D(3 ) needed to raise serum 25(OH)D to > 75 nmol/L. DESIGN The design was a 6-mo , prospect i ve , r and omized , double-blinded , double-dummy , placebo-controlled study of vitamin D(3 ) supplementation .  Serum 25(OH)D was measured by  radioimmunoassay . Vitamin D(3 ) intake was adjusted every 2 mo by use of an algorithm based on serum 25(OH)D concentration . RESULTS A total of 138 subjects entered the study . After 2 dose adjustments , almost all active subjects attained concentrations of 25(OH)D > 75 nmol/L , and no subjects exceeded 220 nmol/L. The mean ( + /-SD ) slope at 9 wk [ defined as 25(OH)D change/baseline dose ] was 0.66 + /- 0.35 (nmol/L)/(microg/d ) and did not differ statistically between blacks and whites . The mean daily dose was 86 microg ( 3440 IU ) . The use of computer simulations to obtain the most participants within the range of 75 - 220 nmol/L predicted an optimal daily dose of 115 microg/d ( 4600 IU ) . No hypercalcemia or hypercalciuria was observed . CONCLUSIONS Determination of the intake required to attain serum 25(OH)D concentrations > 75 nmol/L must consider the wide variability in the dose-response curve and basal 25(OH)D concentrations . Projection of the dose-response curves observed in this convenience sample onto the population of the third National Health and Nutrition Examination Survey suggests a dose of 95 microg/d ( 3800 IU ) for those above a 25(OH)D threshold of 55 nmol/L and a dose of 125 microg/d ( 5000 IU ) for those below that threshold
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 .