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 .
Regional variation and determinants of vitamin D status in sunshine-abundant Thailand
Background Vitamin D insufficiency is highly prevalent . Most of the studies concerning vitamin D status were generated from countries situated at temperate latitudes . It is less clear what the extent of vitamin D insufficiency is in countries situated in the tropics and how geographical regions within country would affect vitamin D status . In the present study , we investigated vitamin D status in Thais according to geographical regions and other risk factors . Methods Subjects consisted of 2,641 adults , aged 15 - 98 years , r and omly selected from the Thai 4th National Health Examination Survey ( 2008 - 9 ) cohort .  Serum 25 hydroxyvitamin D  were measured by liquid chromatography/t and em mass spectrometry . Data were expressed as mean ± SE . Results Subjects residing in Bangkok , the capital city of Thail and , had lower 25(OH)D levels than other parts of the country ( Bangkok , central , northern , northeastern and southern regions : 64.8 ± 0.7 , 79.5 ± 1.1 , 81.7 ± 1.2 , 82.2 ± 0.8 and 78.3 ± 1.3 nmol/L , respectively ; p < 0.001 ) . Within each region , except for the northeastern part of the country , subjects living inside municipal areas had lower circulating 25(OH)D ( central , 77.0 ± 20.9 nmol/L vs 85.0 ± 22.1 nmol/L , p < 0.001 ; north 79.3 ± 22.1 nmol/L vs 86.8 ± 21.8 nmol/L , p < 0.001 ; northeast 84.1 ± 23.3 nmol/L vs 87.3 ± 20.9 nmol/L , p = 0.001 ; south , 76.6 ± 20.5 nmol/L vs 85.2 ± 24.7 nmol/L , p < 0.001 ) . Overall , the prevalence of vitamin D insufficiency was 64.6 % , 46.7 % , and 33.5 % in Bangkok , municipal areas except Bangkok , and outside municipal area in other parts of the country , respectively . In addition , the prevalence of vitamin D insufficiency according to geographical regions was 43.1 % , 39.1 % , 34.2 % and 43.8 % in the central , north , northeast and south , respectively . After controlling for covariates in multiple linear regression analysis , the results showed that low serum 25(OH)D levels were associated with being female , younger age , living in urban and Bangkok . Conclusions Vitamin D insufficiency is common and varies across geographical regions in Thail and
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 .