Orange juice as a source of vitamin D
There’s a short list of food sources of vitamin D.
Researchers from Boston compared the bioavailability of vitamins D2 and D3 from orange juice vs capsules.
First, the details.
- A group of healthy adults received 1000 IU vitamin D3, 1000 IU vitamin D2, or placebo in orange juice or a capsule for 11 weeks at the end of winter.
- Neither the patients nor researchers knew the treatment given — double blind.
And, the results.
- 64% of participants began the study deficient in vitamin D (less than 20 ng/mL).
- Vitamin D from orange juice and capsules were both bioavailable to the body.
- There was no difference in blood levels of vitamin D3 obtained from juice or capsules.
- There was no difference in blood levels between vitamin D2 from juice or capsules.
- There was no significant difference in parathyroid hormone concentrations between the groups.
- Parathyroid hormone stimulates production of active vitamin D in the kidney, which facilitates calcium absorption from the intestines.
The bottom line?
So, fortified orange juice is as good a source of vitamin D as a capsule.
The NIH has published a dietary supplement fact sheet on vitamin D, which includes background and other food sources of the vitamin.
More on the science of vitamin D is here. And a new Medscape review is here.
5/10/10 14:03 JR