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 .
A Randomized Double-Blind Placebo-Controlled Trial of the Effect of Vitamin D3 Supplementation on Breast Density in Premenopausal Women
Background : This double-blind , placebo-controlled parallel group trial assessed whether oral supplementation with 1,000 , 2,000 , or 3,000 IU/day vitamin D3 over one year reduces percent mammographic breast density in premenopausal women . Methods : The trial was conducted between October 2012 and June 2015 , among premenopausal female volunteers from Quebec City ( Quebec , Canada ) . Women were r and omized with ratio 1:1:1:1 to one of four study arms ( 1,000 , 2,000 , or 3,000 IU/day vitamin D3 or placebo ) . The primary outcome was mean change in percent mammographic breast density . Participants and research team were blinded to study arm assignment . Results : Participants ( n = 405 ) were r and omized to receive 1,000 ( n = 101 ) , 2,000 ( n = 104 ) , or 3,000 IU/day ( n = 101 ) vitamin D3 , or a placebo ( n = 99 ) . The primary analysis included 391 participants ( 96 , 99 , 100 , and 96 , respectively ) . After the one-year intervention , mean ± SE change in percent breast density in the arms 1,000 IU/day ( –5.5 % ± 0.5 % ) and 2,000 IU/day ( –5.9 % ± 0.5 % ) vitamin D3 was similar to that in the placebo arm ( −5.7 % ± 0.5 % ) ( P values = 1.0 ) . In the 3,000 IU/day vitamin D3  arm , percent breast density also declined but slightly less ( –3.8 % ± 0.5 % ) compared with placebo arm ( P = 0.03 ) . Adherence to intervention was excellent ( 92.8 % ) , and reporting of health problems was comparable among study arms ( P ≥ 0.95 ) . All participants had normal serum calcium . Conclusions : In premenopausal women , one-year supplementation with 1,000 , 2,000 , or 3,000 IU/day vitamin D3 result ed in a reduction of percent breast density no greater than that seen with the placebo . Impact : At doses of 1,000–3,000 IU/day , vitamin D supplementation will not reduce breast cancer risk through changes in breast density . Cancer Epidemiol Biomarkers Prev ; 26(8 ) ; 1233–41 . © 2017 AACR
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 .