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 and Testosterone in Healthy Men: A Randomized Controlled Trial
Context : Available evidence shows an association of vitamin D with and rogen levels in men . However , results from preliminary r and omized controlled trials ( RCTs ) are conflicting . Objective : To evaluate whether vitamin D supplementation increases total testosterone ( TT ) levels in healthy men . Design : The Graz Vitamin D&TT‐ RCT is a single‐center , double‐blind , r and omized , placebo‐controlled trial conducted between December 2012 and January 2017 . Setting : Endocrine outpatient clinic at the Medical University of Graz , Austria . Participants : Ninety‐eight healthy men with TT levels ≥10.4 nmol/L and 25‐hydroxyvitamin D [ 25(OH)D ] levels < 75 nmol/L completed the study . Intervention : Subjects were r and omly assigned to receive 20,000 IU/wk of vitamin D3 ( n = 50 ) or placebo ( n = 50 ) for 12 weeks . Main Outcome Measures : Primary outcome was TT measured using mass spectrometry . Secondary outcomes were free testosterone , sex hormone‐binding globulin , estradiol , follicle‐stimulating hormone , and luteinizing hormone levels ; free and rogen index ; metabolic characteristics ; and body composition . Results : In healthy men [ mean values ± st and ard deviation : age , 39 years ( ±13 years ) ; 25(OH)D level , 53.3 nmol/L ( ±18.3 nmol/L ) ; TT , 19.1 nmol/L ( ±5.6 nmol/l ) ] , no significant treatment effect on TT was found ; however , there were significant effects on quantitative insulin sensitivity check index ( QUICKI ) and a trend toward decreased Matsuda index . In the treatment group , median ( interquartile range ) changes for TT , QUICKI , and Matsuda index were 0.5 nmol/L ( −0.63 to 0.63 nmol/L ; P = 0.497 ) , −0.02 ( −0.04 to 0.01 ; P = 0.034 ) , and −0.9 ( −3.2 to 0.8 ; P = 0.051 ) , respectively . Conclusion : Vitamin D treatment had no effect on TT levels in middle‐aged healthy men with normal baseline TT , but it significantly decreased QUICKI . Additional studies investigating vitamin D effects on TT and insulin sensitivity in healthy men are required
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 .