Fortification of orange juice with vitamin D2 or vitamin D3 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 D-2 vitamin 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. Am, J Clin Mar 2010;91:1621-6.