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

Abstract

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 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.

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.

FIGURE 1

A: Mean (±SEM) total 25-hydroxyvitamin D [25(OH)D] concentrations over time after the oral administration of 1000 IU vitamin D₃ in orange juice (•; n = 18), 1000 IU vitamin D₃ in capsules (▪; n = 20), or unfortified orange juice plus placebo capsules (♦; n = 15). No statistically significant differences were observed between areas under the curve for serum total 25(OH)D between the vitamin D₃ in orange juice and vitamin D₃ capsule groups (one-factor ANOVA, P = 0.084). B: Mean (±SEM) total 25(OH)D concentrations over time after oral administration of 1000 IU vitamin D₂ in orange juice (•; n = 17), 1000 IU vitamin D₂ in capsules (▪; n = 16), or unfortified orange juice plus placebo capsules (♦; n = 15). No statistically significant differences were observed between areas under the curve for serum total 25(OH)D between the vitamin D₂ in orange juice and vitamin D₂ capsule groups (one-factor ANOVA, P = 0.084).

FIGURE 2

A: Mean (±SEM) serum 25-hydroxyvitamin D [25(OH)D₃] concentrations over time after oral administration of 1000 IU vitamin D₃ in orange juice (•; n = 18), 1000 IU vitamin D₃ in capsules (▪; n = 20), or unfortified orange juice plus placebo capsules (♦; n = 15). The area under the curve for serum 25(OH)D₃ after consumption of vitamin D₃ in orange juice and after vitamin D₃ in capsules was not significantly different (one-factor ANOVA, P > 0.05). B: Mean (±SEM) serum 25(OH)D₂ concentrations over time after oral administration of 1000 IU vitamin D₂ in orange juice (•; n = 17), 1000 IU vitamin D₂ in capsules (▪; n = 16), or unfortified orange juice plus placebo capsules (♦; n = 15). The area under the curve for serum 25(OH)D₂ after consumption of vitamin D₂ in orange juice and of the vitamin D₂ capsules was not significantly different (one-factor ANOVA, P > 0.05).