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 .
Changes in the human transcriptome upon vitamin D supplementation
Vitamin D is hydroxylated in the liver and kidneys to its active form , which can bind to the vitamin D receptor ( VDR ) . The VDR is present in a wide variety of different cells types and tissues and acts as a transcription factor . Although activation of the VDR is estimated to regulate expression of up to 5 % of the human genome , our study is the first analysing gene expression after supplementation in more than 10 subjects . Subjects of a r and omized controlled trial ( RCT ) received either vitamin D3 ( n=47 ) in a weekly dose of 20,000 IU or placebo ( n=47 ) for a period of three to five years . For this study , blood sample s for preparation of RNA were drawn from the subjects and mRNA gene expression in blood was determined using microarray analysis . The two study groups were similar regarding gender , age , BMI and duration of supplementation , whereas the mean serum 25-hydroxyvitamin D ( 25(OH)D ) level as expected was significantly higher in the vitamin D group ( 119 versus 63nmol/L ) . When analysing all subjects , nearly no significant differences in gene expression between the two groups were found . However , when analysing men and women separately , significant effects on gene expression were observed for women . Furthermore , when only including subjects with the highest and lowest serum 25(OH)D levels , additional vitamin D regulated genes were disclosed . Thus , a total of 99 genes ( p≤0.05 , log2 fold change ≥|0.2| ) were found to be regulated , of which 72 have not been published before as influenced by vitamin D. These genes were particularly involved in the interleukin signaling pathway , oxidative stress response , apoptosis signaling pathway and gonadotropin releasing hormone receptor pathway . Thus , our results open the possibility for many future studies
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 .