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, placebo-controlled trial of vitamin D supplementation to improve glycaemia in overweight and obese African Americans.
AIMS Vitamin D deficiency may increase the risk for type 2 diabetes . African Americans tend to have poor vitamin D status and increased risk of diabetes , but effects of vitamin D supplementation on components of diabetes risk have not been tested in this group . This study was conducted to determine whether vitamin D supplementation improves insulin secretion , insulin sensitivity and glycaemia in African Americans with prediabetes or early diabetes . METHODS In this r and omized , placebo-controlled trial , we examined the effect of 4000 IU/day vitamin D(3 , ) on glycaemia and contributing measures including insulin secretion , insulin sensitivity and the disposition index over 12 weeks in 89 overweight or obese African Americans with prediabetes or early diabetes . Outcome measures were derived from oral glucose tolerance testing . RESULTS Mean plasma 25-hydroxyvitamin D was about 40 nmol/l in the placebo and vitamin D groups at baseline and increased to 81 nmol/l with supplementation . Insulin sensitivity decreased by 4 % in the vitamin D group compared with a 12 % increase in the placebo group ( p = 0.034 ) . Insulin secretion increased by 12 % in the vitamin D group compared with a 2 % increase in the placebo group ( p = 0.024 ) , but changes in the disposition index were similar across groups . There was no effect of supplementation on post-load glucose or other measures of glycaemia . CONCLUSIONS Supplementation with 4000 IU/day vitamin D(3 ) successfully corrected vitamin D insufficiency and had divergent effects on insulin secretion and sensitivity with no overall effect on disposition index or glycaemia . In this study , vitamin D supplementation for 3 months did not change the pathophysiology of prediabetes in overweight and obese African Americans
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 .