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 .
Skeletal and hormonal responses to vitamin D supplementation during sunlight deprivation in Antarctic expeditioners
Summary Sunlight deprivation results in vitamin D deficiency but serum vitamin D levels can be maintained above 50nmol/L when supplemented with 50,000IU at least every alternate month . Introduction Anta rct ic expeditioners are exposed to prolonged sunlight deprivation result ing in vitamin D deficiency . We hypothesised that monthly dosing of 50,000 IU vitamin D ( ~1,600 IU daily ) will increase serum 25-hydroxyvitamin D ( 25(OH)D ) , suppress parathyroid hormone ( PTH ) and improve bone mineral density ( BMD ) , 50,000 IU alternate months ( ~800 IU daily ) will maintain these measures , while a single 50,000 IU dose pre-departure ( ~1,00 IU daily ) will not be protective . Methods This was a r and omised double-blind study involving 110 healthy adults : 91 males , mean age 41 years ( range 24–65 years ) working in Anta rct ica for up to 12 months , who we administered 50,000 IU vitamin D3 monthly , alternate months or a single dose pre-departure  . Serum 25(OH)D , PTH , osteocalcin , CTx and calcium were assessed at baseline , mid- and end of expedition . Proximal femur and lumbar spine BMD were assessed pre- and post-expedition . Results Baseline 25(OH)D was 59 ± 14 nmol/L. By mid-expedition , 25(OH)D increased by 7 nmol/L in those supplemented monthly ( p < 0.05 ) and remained unchanged in those supplemented in alternate months . In those given a single dose pre-departure , 25(OH)D decreased by 8 nmol/L ( p < 0.05 ) and PTH increased by 27 % ( p < 0.09 ) . Serum osteocalcin increased by ~22 % in all groups but BMD remained unchanged . If serum 25(OH)D was > 50 nmol/L at baseline , 25(OH)D was maintained above this level with all regimens . If 25(OH)D was < 50 nmol/L at baseline , monthly or alternate month regimens were needed to achieve levels > 50 nmol/L , the single pre-departure dose was ineffective . Conclusion During sunlight deprivation of up to 12 months , serum 25(OH)D levels can be maintained above 50 nmol/L when expeditioners are provided with 50,000 I U at least every alternate month
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 .