Featured Research

from universities, journals, and other organizations

Studies Rebut Concept That Body Stores Vitamin A-Making Substances

Date:
August 14, 1998
Source:
University Of Illinois At Urbana-Champaign
Summary:
Efforts to battle vitamin A deficiency have been thrown a curve: Carotenoids that promote vitamin A production -- and are often consumed in mass quantities when available -- are not sufficiently stored and converted to vitamin A, according to new research.

CHAMPAIGN, Ill. -- Efforts to battle vitamin A deficiency have been thrown a curve: Carotenoids that promote vitamin A production -- and are often consumed in mass quantities when available -- are not sufficiently stored and converted to vitamin A, according to new research.

Related Articles


Vitamin A deficiency causes blindness and has been linked with poor growth in children, immunity problems and death. The World Health Organization estimates that 2.8 million preschool children are at risk of blindness, and the health of 251 million people is compromised.

"In many countries, either because of lack of access or because of religious preference, vitamin A is not in the diet or is consumed in very small amounts," said John Erdman, director of the University of Illinois Division of Nutritional Sciences. "You only get pre-formed vitamin A from animal foods such as liver, dairy products and fish oil. Millions of people don't get these highly bioavailable sources."

In the absence of animal-based sources, vitamin A supplements or an infusion of carotenoid-rich vegetables can be substituted. Some carotenoids, particularly beta carotene, act as precursors to vitamin A. The carotenoids convert into retinol, which is the active form of the vitamin.

The new research, involving two studies, was performed on Mongolian gerbils and reported in the July issue of the Journal of Nutrition. Implications of the work for humans is not completely clear. However, since gerbils convert beta carotene to vitamin A at a ratio similar to humans (a discovery reported earlier this year in the same journal by Erdman and colleagues), the new findings are worthy of a closer look, Erdman said. A followup study with the same animal model begins this month.

"We found that stored carotenoids from a previously consumed diet were not converted to vitamin A when the vitamin was removed from the diet," Erdman said. "This is the first scientific evidence that questions the utility of this vitamin A precursor."

There was a rapid loss of beta carotene from the two pools in the gerbils' liver. One pool was lost slowly; the second, which included the most beta carotene, was lost rapidly. High levels of beta carotene absorbed in tissues failed to improve vitamin A status, and feeding pre-formed vitamin A without beta carotene failed to slow the loss of stores of previously fed beta carotene.

"Without continual feeding of beta carotene in the diet, most of the tissue beta carotene is eventually depleted," Erdman said. "If stored or accumulated beta carotene is not converted to vitamin A when initially absorbed, beta carotene provides no vitamin A value.

"A popular public health approach in some countries with rampant vitamin A deficiency is to promote consumption of fruits and vegetables high in beta carotene as they are available. It was assumed this would offer protection for much of the year. This approach will have to be revisited."

Coauthors were Erdman, technician Christine M. Lee and former graduate student Angela J. Thatcher. Funding came from the National Research Initiative of the U.S. Department of Agriculture.


Story Source:

The above story is based on materials provided by University Of Illinois At Urbana-Champaign. Note: Materials may be edited for content and length.


Cite This Page:

University Of Illinois At Urbana-Champaign. "Studies Rebut Concept That Body Stores Vitamin A-Making Substances." ScienceDaily. ScienceDaily, 14 August 1998. <www.sciencedaily.com/releases/1998/08/980814064805.htm>.
University Of Illinois At Urbana-Champaign. (1998, August 14). Studies Rebut Concept That Body Stores Vitamin A-Making Substances. ScienceDaily. Retrieved April 19, 2015 from www.sciencedaily.com/releases/1998/08/980814064805.htm
University Of Illinois At Urbana-Champaign. "Studies Rebut Concept That Body Stores Vitamin A-Making Substances." ScienceDaily. www.sciencedaily.com/releases/1998/08/980814064805.htm (accessed April 19, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, April 19, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Dr. Oz Under Fire For 'Quack Treatments' Yet Again

Dr. Oz Under Fire For 'Quack Treatments' Yet Again

Newsy (Apr. 17, 2015) Ten doctors signed a letter urging Columbia University to drop Dr. Oz as vice chair of its department of surgery, saying he plugs "quack" treatments. Video provided by Newsy
Powered by NewsLook.com
Scientists Find Link Between Gestational Diabetes And Autism

Scientists Find Link Between Gestational Diabetes And Autism

Newsy (Apr. 17, 2015) Researchers who analyzed data from over 300,000 kids and their mothers say they&apos;ve found a link between gestational diabetes and autism. Video provided by Newsy
Powered by NewsLook.com
Video Messages Help Reassure Dementia Patients

Video Messages Help Reassure Dementia Patients

AP (Apr. 17, 2015) Family members are prerecording messages as part of a unique pilot program at the Hebrew Home in New York. The videos are trying to help victims of Alzheimer&apos;s disease and other forms of dementia break through the morning fog of forgetfulness. (April 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins