Vitamin D - Health Benefits and Effects

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Note that the proceedings will only be available free to

non-subscribers of the AJCN through August 15; after that date, non-subscribers

to the journal will be required to pay a fee to access the proceedings.

Jack on August 12 at 1:43 pm

Vitamin D - Health Benefits and Effects - The

NIH Office of the Dietary Supplements (ODS) has announced the availability of

the proceedings of the NIH conference, titled " Vitamin D and Health in the

21st Century: An Update " which is to be published as a supplement to the

August 2008 issue of the American Journal of Clinical Nutrition - ODS notes

that " ... The data are strongest in the area of bone health among elderly

men and post-menopausal women, suggesting that increased vitamin D intake can

improve bone health and prevent falls. For other age groups and health issues,

though, it is too early to say conclusively whether more vitamin D might be

beneficial ... "

Document Title: The title of the August 12, 2008 NIH ODS News

Release is " Key Gaps Remain in Understanding Health Effects of Vitamin D;

Special Journal Issue Summarizes What We Know and What We Need to Learn "

Organization: Office of the

Dietary Supplements (ODS) of the National Institutes of Health

Summary: The text of the August

12, 2008 ODS News Release follows

Despite considerable progress in research to understand the health effects of

vitamin D, experts convened by the NIH to review the available data found major

gaps in the evidence. The data are strongest in the area of bone health among

elderly men and post-menopausal women, suggesting that increased vitamin D

intake can improve bone health and prevent falls. For other age groups and

health issues, though, it is too early to say conclusively whether more vitamin

D might be beneficial.

An in-depth review of current research on the health effects of vitamin D is

being published as the proceedings of the NIH conference, " Vitamin D and

Health in the 21st Century: An Update " , which will appear in an August

2008 supplement to the American Journal of Clinical Nutrition.

Intriguing findings from research conducted in recent years have led to

increased interest in vitamin D among health care providers, researchers, and

the general public, including concern about possibly widespread deficiency,

calls for supplementation, and even use of large doses of vitamin D as

treatments for a variety of conditions.

" Given recent findings, it’s easy to see why people are so

enthusiastic about the potential power of vitamin D, but we must recognize the

limitations of any study and exercise caution when making broad public health

recommendations, " said Frances Picciano, Ph.D., a senior nutrition

research scientist in the NIH Office of Dietary Supplements, who co-authored an

overview of the conference included in the journal supplement. " This is a

very complex set of issues and there is still a lot we don’t know about

how vitamin D levels affect health, especially across different age groups and

ethnic populations. "

" It’s tempting to think that an essential nutrient is safe at any

level ­ that if some is good, more is better, " said M. Coates, Ph.D.,

director of the Office of Dietary Supplements. " We’ve learned that

this isn’t always true, and there are potential harms associated with

high levels of many nutrients. "

Participants in the NIH conference identified a number of limitations of the

existing evidence on vitamin D, including:

Many studies have failed to control for factors that could confuse study

findings, such as diet, baseline vitamin D status, age, disease, season (as

relevant to sun exposure), and physical activity.

Few studies have examined the effects of vitamin D independent of calcium or

other nutrients.

Reliable data on the vitamin D content of foods is not available.

Existing laboratory tests used to measure vitamin D levels in blood vary

widely.

Preliminary research findings suggest a role for vitamin D in preventing

chronic diseases such as diabetes, immune function, and cancer, but further

study is needed.

Research has not identified the vitamin D levels needed to achieve desired

health outcomes in people at various life and reproductive stages and in

dark-skinned individuals.

Vitamin D is an essential component in bone health that helps ensure that the

body absorbs calcium, which is critical for building strong, healthy bones.

People get this nutrient from three sources: sunlight, dietary supplements, and

foods. Most people meet their vitamin D needs through exposure to sunlight, but

questions remain about what amount of sun exposure would yield beneficial

levels of vitamin D without unacceptably elevating skin cancer risk. Very few

foods naturally contain vitamin D, so much of the vitamin D in Americans’

diets comes from fortified foods such as milk and cereal. The flesh of certain

fish such as salmon, tuna, and mackerel and fish liver oils are among the best

naturally-occurring sources. Small amounts of vitamin D are found in beef

liver, cheese, and egg yolks.

It is possible to get the currently recommended amounts of vitamin D from diet.

Two glasses of vitamin D-fortified milk per day, for example, provides enough

vitamin D for a healthy person under age 50. But individuals who are not

consuming vitamin D-rich or fortified foods, or getting regular sun exposure

may want to consult a health care provider about taking supplements to ensure

adequate intake. To learn about vitamin D intake recommendations for different

age groups, read the Office of Dietary Supplements’ vitamin D fact sheet

at http://dietary-supplements.info.nih.gov/factsheets/vitamind.asp

Without sufficient vitamin D, bones can become thin, brittle, or misshapen.

Vitamin D deficiency can lead to rickets in children and osteomalacia

(softening of the bones) in adults. Together with calcium, vitamin D also helps

protect older adults from developing osteoporosis. However, excess vitamin D

intake can also cause harmful side effects, including nausea, vomiting,

diarrhea, constipation and development of kidney stones. Healthcare providers

may check vitamin D blood levels in individuals at increased risk for

deficiency such as breastfed infants, older adults, people with limited sun

exposure, people with dark skin, people with fat malabsorption, and people who

are obese.

Investigations of vitamin D’s health effects are expanding and areas of

promising research include its role in type 1 diabetes, some cancers,

autoimmune diseases such as multiple sclerosis, and infectious diseases such as

tuberculosis.

In light of recent research, some advocates and researchers have called for a

review of the U.S. Dietary Reference Intakes for vitamin D. Current

recommendations for daily vitamin D intake were developed in 1997 by the Food

and Nutrition Board of the Institute of Medicine. The U.S. Department of Health

and Human Services, in collaboration with the U.S. Departments of Agriculture

and Defense, and Health Canada

are currently in discussions with the Institute of Medicine

to revisit the recommendations.

The American Journal of Clinical Nutrition supplement is available to

subscribers at http://www.ajcn.org/, and contains

an overview of the conference, invited papers from many of the conference

speakers, and a summary of the roundtable discussion held following the

conference. The supplement may be accessed via the ODS website, at http://ods.od.nih.gov/news/AJCN2008.aspx

.. The American Journal of Clinical Nutrition is published by the American

Society for Nutrition ( http://www.nutrition.org/ ).

To learn more about vitamin D or other dietary supplements through fact sheets,

databases, and other research resources, please visit the ODS website ( http://dietary-supplements.info.nih.gov/index.aspx

).

The Office of Dietary Supplements was established in 1995 as a result of the

Dietary Supplement Health and Education Act. The mission of ODS is to

strengthen knowledge and understanding of dietary supplements by evaluating

scientific information, stimulating and supporting research, disseminating

research results, and educating the public to foster an enhanced quality of

life and health for the U.S. population.

The National Institutes of Health (NIH) ­ The Nation's Medical Research Agency ­

includes 27 Institutes and Centers and is a component of the U.S. Department of

Health and Human Services. It is the primary federal agency for conducting and

supporting basic, clinical and translational medical research, and it

investigates the causes, treatments, and cures for both common and rare

diseases. For more information about NIH and its programs, visit www.nih.gov

Source: August 12, 2008 NIH ODS

News Release access to the journal supplement which is posted on the ODS www

site.

Web site: The August 12, 2008 NIH

ODS News Release is posted at

http://www.nih.gov/news/health/aug2008/ods-12.htm

The proceedings of the conference are available at no cost to non-subscribers

of the journal until Friday, August 15, 2008 at

http://ods.od.nih.gov/news/AJCN2008.aspx

* After August 15, 2008 the proceedings will be available to non-subscribers of

the AJCN for a fee at

http://www.ajcn.org/misc/supplist.shtml#2008

Contact: The contact listed on the

NIH News Release is Kelli Marciel at ; e-mail: Kelli.Marciel@...