Daily Requirement of Vitamin D Takes a Dip by 400 IU

by Julia Samuel on  April 3, 2017 at 4:58 PM Research News
RSS Email Print This Page Comment
Font : A-A+

The Recommended Dietary Allowance (RDA) for vitamin D intake drops from 800 to 400 International Units (IU) per day, after re-measurement of vitamin D by improved technology.
Daily Requirement of Vitamin D Takes a Dip by 400 IU
Daily Requirement of Vitamin D Takes a Dip by 400 IU

"The RDA is easily achievable with a supplement of 400 IU in winter, when vitamin D levels are lowest in North America," said principal investigator J. Christopher Gallagher, M.D., professor and director of the Bone Metabolism Unit in the Division of Endocrinology of Creighton University School of Medicine in Omaha, Neb.

"This has important ramifications for public health recommendations. The amount of vitamin D needed, 400 IU daily, is less than the figure recommended by Institute of Medicine," said Gallagher, the study's principal investigator.

"In estimating the RDA for vitamin D intake, the laboratory method used for measuring serum 25-hydroxyvitamin D (25(OH)D) can affect the results," he said. "The estimated RDA based on the older immunoassay (DiaSorin S.p.A., Salugia, Italy) system was 800 IU daily, whereas the newer liquid chromatography tandem-mass spectrometry (LC-MS/MS) technique estimated that 400 IU daily would meet the RDA."

In their earlier double-blind dose-response clinical trial in the winter and spring of 2007 to 2008, Gallagher and his colleagues enrolled 163 healthy postmenopausal Caucasian women 57 through 90 years of age with vitamin D insufficiency and followed them for 1 year. The women were at least 7 years postmenopausal and they had vitamin D insufficiency based on the World Health Organization cutoff (serum 25(OH)D 20 ng/ml or lower).

The participants were randomized to one of seven vitamin D3 doses: 400, 800, 1600, 2400, 3200, 4000, 4800 IU/day or placebo, for 1 year, and all the women were given calcium supplements to maintain a total calcium intake.

After analyzing the samples and estimating the RDA using the older immunoassay, the authors reported that 800 IU daily would meet the vitamin D intake requirement for 97.5 percent of the population.

But now that liquid chromatography mass spectrometry (LC-MS/MS) has become the gold standard for measuring 25(OH)D, the researchers have reanalyzed the original samples using this new technology. Able to determine a more precise dose-response curve, they have calculated the RDA for vitamin D to be 400 IU daily.

"Remember, this RDA is for bone health only," Gallagher cautioned. "It may be different for other diseases. Although trials looking into cancer, diabetes, and other diseases are ongoing, we do not have information about this yet."



Source: Eurekalert

Post your Comments

Comments should be on the topic and should not be abusive. The editorial team reserves the right to review and moderate the comments posted on the site.
* Your comment can be maximum of 2500 characters
Notify me when reply is posted
I agree to the terms and conditions

Related Links

More News on:

Calcium and Vitamin Supplements Rickets Vitamin Supplements Vitamin C / Ascorbic acid Vitamin B6 Vitamin B9 Vitamin B-12 Vitamin-F Amyotrophic Lateral Sclerosis (ALS) Dandy Walker Syndrome 

News A - Z

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

News Search

Medindia Newsletters

Subscribe to our Free Newsletters!

Terms & Conditions and Privacy Policy.

Stay Connected

  • Available on the Android Market
  • Available on the App Store

Facebook

News Category

News Archive