Vitamin D as Bioavailable in O.J. as Supplements

BOSTONDrinking a glass of vitamin D-fortified orange juice is as effective as taking a supplement, according to a new study from the Boston University School of Medicine (Am J Clin Nutr. 2010 Apr 28). Researchers found both vitamin D2 and vitamin D3 were equally bioavailable in orange juice and capsules.

They conducted a randomized, placebo-controlled, double blind study in healthy adults aged 18 to 84 years. Participants were divided into groups of 15 to 20 people, each drinking a glass of orange juice every morning and swallowing a capsule every night for 11 weeks at the end of winter. The orange juices were either fortified with 1,000 IU of vitamin D3 or 1,000 IU vitamin D2; or with a placebo. The supplements either contained 1,000 IU of vitamin D3, 1,000 IU of vitamin D2; or were a placebo. A total of 64 percent of subjects began the study deficient in vitamin D with 25-hydroxyvitamin D (25[OH]D) concentrations less than 20 ng/mL.

At the end of the study, researchers found no significant difference in serum 25(OH)D between subjects who consumed vitamin Dfortified orange juice and those who consumed vitamin D supplements (P=0.084). No significant difference in serum 25(OH)D3 was observed between subjects who consumed vitamin D3fortified orange juice and vitamin D3 capsules (P>0.1). Similarly, no significant difference in serum 25(OH)D2 was observed between subjects who consumed vitamin D2fortified orange juice and vitamin D2 capsules (P>0.1). Those who received both placebos showed no improvement in vitamin D levels.

The study was supported by the National Center for Research Resources, a component of the National Institutes of Health; and the Beverage Institute for Health & Wellness, a division of Coca-Cola North America, Atlanta.