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.

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. 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. A randomized, 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. 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). Vitamin D(2) and vitamin D(3) are equally bioavailable in orange juice and capsules.