[PHNUTR-L] Vitamin D2 is as effective as vitamin D3 in maintaining concentrations of 25-hydroxyvitamin D

[Kathrynne Holden]

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Public release date: 2-Jan-2008
http://www.eurekalert.org/pub_releases/2008-01/bu-vdi010208.php

Contact: Michelle Roberts
michelle.roberts at bmc.org
617-638-8491
Boston University

Vitamin D2 is as effective as vitamin D3 in maintaining concentrations 
of 25-hydroxyvitamin D

Boston, MA— Researchers from Boston University School of Medicine (BUSM) 
have found that vitamin D2 is equally as effective as vitamin D3 in 
maintaining 25-hydroxyvitamin D status. The study appears online in the 
December 2007 issue of the Journal of Clinical Endocrinology & Metabolism.

Researchers studied healthy adults aged 18-84 who received either 
placebo, 1,000 International Units (IU) of vitamin D3, 1,000 IU of 
vitamin D2, or 500 IU of vitamin D2 plus 500 IU of vitamin D3 daily for 
three months at the end of winter to establish what effect it had on 
circulating levels of total 25 (OH)D as well as 25(OH)D2 and 25(OH)D3. 
Sixty percent of the adults were vitamin D deficient at the start of the 
study.

Adults who received the placebo capsule daily for three months 
demonstrated no significant change in their total 25(OH)D levels during 
the winter and early spring. Adults who ingested 1,000 vitamin D2/d 
gradually increased their total 25(OH)D levels during the first six 
weeks. Adults who ingested 1,000 IU of vitamin D3 had a baseline 25(OH)D 
that was statistically no different from the baselines of either the 
placebo group or the groups that took 1,000 IU of vitamin D2/d or 500 IU 
vitamin D2 plus 500 IU vitamin D3/d. The vitamin D3 group increased 
their serum 25(OH)D levels similar to that of the group that ingested 
vitamin D2.

The circulating levels of 25-hydroxyvitamin D increased to the same 
extent in the groups that received 1,000 IU daily as vitamin D2, vitamin 
D3, or a combination of 500 IU vitamin D2 and 500 IU vitamin D3. The 
25-hydroxyvitamin D3 levels did not change in the group that received 
1,000 IU vitamin D2 daily. One thousand IU of vitamin D2 or vitamin D3 
did not raise 25-hydroxyvitamin D levels in vitamin D deficient subjects 
above 30 ng/ml.

According to BUSM researchers, vitamin D2 has been the main stay for the 
prevention and treatment of vitamin D deficiency in children and adults 
and as little as 100 IU of vitamin D2 was found to be effective in the 
prevention of rickets. Both vitamin D2 and vitamin D3 form 
25-hydroxyvitamin D.

Michael Holick, PhD, MD, director of the General Clinical Research 
Center and professor of medicine, physiology and biophysics at BUSM and 
senior author of this study, is an internationally recognized expert in 
vitamin D and skin research. Most recently, he gave the keynote address 
to the Indian Endocrine Society in India.

“The maintenance of the serum 25(OH)D3 levels was most likely due to the 
release of vitamin D3 stored in the body fat since skin synthesis of 
vitamin D3 does not occur during the winter in Boston,” said Holick, who 
is also director of the Bone Healthcare Clinic and the vitamin D, Skin 
and Bone Research Laboratory at Boston University Medical Center.

“One thousand IU of vitamin D2 daily was as effective as 1,000 IU of 
vitamin D3 in maintaining serum 25-hydroxyvitamin D levels and did not 
negatively influence serum 25-hydroxyvitamin D levels,” said Holick. 
“Therefore, vitamin D2 is equally as effective as vitamin D3 in 
maintaining 25-hydroxyvitamin D status.”

###

Quest Diagnostics, the nation’s leading provider of diagnostics testing, 
information and services, analyzed the specimens used in the study.

For more information on Boston University Medical Center, please visit 
http://www.bumc.bu.edu/.
-- 
Kathrynne Holden, MS, RD < fivestar at nutritionucanlivewith.com >
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