Inclusion of 95 % range in the model to account for inter-individual variability increased the predicted intake of vitamin D needed to maintain serum 25(OH)D ≥ 50 nmol/l to 930 IU/d .
Fortification of orange juice with vitamin D(2) or vitamin D(3) is as effective as an oral supplement in maintaining vitamin D status in adults.
BACKGROUND Vitamin D has been added to calcium-fortified orange juice . It is unknown whether vitamin D is as bioavailable from orange juice as it is from supplements . OBJECTIVES The objective was to compare the bioavailability of vitamin D(2 ) and vitamin D(3 ) from orange juice with that from vitamin D(2 ) and vitamin D(3 ) supplements . A secondary aim was to determine which form of vitamin D is more bioavailable in orange juice . DESIGN A r and omized , placebo-controlled , double-blind study was conducted in healthy adults aged 18 - 84 y ( 15 - 20/group ) who received 1000 IU vitamin D(3 ) , 1000 IU vitamin D(2 ) , or placebo in orange juice or capsule for 11 wk at the end of winter . RESULTS A total of 64 % of subjects began the study deficient in vitamin D ( ie , 25-hydroxyvitamin D [ 25(OH)D ] ) concentrations < 20 ng/mL ) . Analysis of the area under the curve showed no significant difference in serum 25(OH)D between subjects who consumed vitamin D-fortified orange juice and those who consumed vitamin D supplements ( P = 0.084 ) . No significant difference in serum 25(OH)D(3 ) was observed between subjects who consumed vitamin D(3)-fortified orange juice and vitamin D(3 ) capsules ( P > 0.1 ) . Similarly , no significant difference in serum 25(OH)D(2 ) was observed between subjects who consumed vitamin D(2)-fortified orange juice and vitamin D(2 ) capsules ( P > 0.1 ) . No significant overall difference in parathyroid hormone concentrations was observed between the groups ( P = 0.82 ) . CONCLUSION Vitamin D(2 ) and vitamin D(3 ) are equally bioavailable in orange juice and capsules
Inclusion of 95 % range in the model to account for inter-individual variability increased the predicted intake of vitamin D needed to maintain serum 25(OH)D ≥ 50 nmol/l to 930 IU/d .