This study should provide valuable information about the bioavailability of both vitamin D2 and vitamin D3 formulated in orange juice compared to vitamin D2 and vitamin D3 formulated in a pill and taken with water. It is anticipated based on our previous observation that the vitamin D2 and vitamin D3 in orange juice will be at least 50% more effective in raising the blood levels of 25(OH)D than when taken in pill form.~This study will evaluate the bioavailability and metabolism of vitamin D2 and vitamin D3 in combination in tablet form. The results should provide important information as to whether a physiologic dose of vitamin D2 has a negative effect on circulating levels of 25-hydroxyvitamin D2 [25(OH)D2 ] and on 25-hydroxyvitamin D3 [25(OH)D3]. Results from this study have important implications for expanding the adequate intake (AI) recommendations for vitamin D2 and vitamin D3 for adults.
The purpose of this study was to determine whether vitamin D2 and vitamin D3 in orange juice are effective at raising vitamin D levels in the blood and if vitamin D2 and vitamin D3 in orange juice raised blood levels of 25(OH)D as well as vitamin D3 and vitamin D2 supplements.