Featured Research

from universities, journals, and other organizations

Low vitamin D levels associated with cognitive decline

Date:
July 13, 2010
Source:
JAMA and Archives Journals
Summary:
Older adults with low levels of vitamin D appear more likely to experience declines in thinking, learning and memory over a six-year period, according to a new study.

Older adults with low levels of vitamin D appear more likely to experience declines in thinking, learning and memory over a six-year period, according to a report in the July 12 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

An estimated 40 percent to 100 percent of older adults in the United States and Europe are deficient in vitamin D, according to background information in the article. This deficiency has been linked to fractures, various chronic diseases and death. Vitamin D may help prevent the degeneration of brain tissue by having a role in formation of nervous tissue, maintaining levels of calcium in the body, or clearing of beta-amyloid, the substance that forms the brain plaques and tangles associated with Alzheimer's disease.

David J. Llewellyn, Ph.D., of University of Exeter, England, and colleagues assessed blood levels of vitamin D in 858 adults who were age 65 or older when the study began in 1998. Participants completed interviews and medical examinations and provided blood samples. At the beginning of the study and again after three and six years, they repeated three tests of cognitive function -- one assessing overall cognition, one focusing on attention and one that places greater emphasis on executive function, or the ability to plan, organize and prioritize.

Participants who were severely deficient in vitamin D (having blood levels of 25-hydroxyvitamin D of less than 25 nanomoles per liter) were 60 percent more likely to have substantial cognitive decline in general over the six-year period and 31 percent more likely to experience declines on the test measuring executive function than those with sufficient vitamin D levels. "The association remained significant after adjustment for a wide range of potential confounders and when analyses were restricted to elderly subjects who were non-demented at baseline," the authors write. However, no significant association was seen for the test measuring attention.

"If future prospective studies and randomized controlled trials confirm that vitamin D deficiency is causally related to cognitive decline, then this would open up important new possibilities for treatment and prevention," the authors conclude.

Editorial: Randomized Controlled Trials Needed to Examine Vitamin D's Role

"Vitamin D has been known for many years to play a critical role in skeletal health, such that very low levels of this hormone (less than 20 nanomoles per liter) can cause osteomalacia, a disorder of impaired bone mineralization," write Andrew Grey, M.D., and Mark Bolland, M.B.Ch.B., Ph.D., of University of Auckland, New Zealand, in an accompanying editorial. "More recently, observational studies have reported inverse associations between levels of serum 25-hydroxyvitamin D, the metabolite that best reflects overall vitamin D status, and the risk of a wide range of disease, including cancer, vascular disease, infectious conditions, autoimmune diseases, osteoporosis, type 2 diabetes mellitus and obesity."

"The results of these observational studies have prompted calls for widespread treatment of individuals with low levels of vitamin D and the establishment of public health programs aimed at raising the population levels of vitamin D to 'healthy' values," the authors write.

"It is now time to test the various hypotheses generated by observational studies of vitamin D, including that of Llewellyn et al, in adequately designed and conducted randomized controlled trials," they conclude. "Very importantly, such trials will also provide an opportunity to systematically assess potential harms of vitamin D supplementation, an issue that has been largely overlooked or dismissed. We should invest in trials that provide the best possible evidence on the benefits and risks of vitamin D before we invest in costly, difficult and potentially unrewarding interventional strategies."


Story Source:

The above story is based on materials provided by JAMA and Archives Journals. Note: Materials may be edited for content and length.


Journal References:

  1. David J. Llewellyn; Iain A. Lang; Kenneth M. Langa; Graciela Muniz-Terrera; Caroline L. Phillips; Antonio Cherubini; Luigi Ferrucci; David Melzer. Vitamin D and Risk of Cognitive Decline in Elderly Persons. Arch Intern Med, 2010; 170 (13): 1135-1141 [link]
  2. Andrew Grey; Mark Bolland. Vitamin D: A Place in the Sun? Arch Intern Med, 2010; 170 (13): 1099-1100 [link]

Cite This Page:

JAMA and Archives Journals. "Low vitamin D levels associated with cognitive decline." ScienceDaily. ScienceDaily, 13 July 2010. <www.sciencedaily.com/releases/2010/07/100712162554.htm>.
JAMA and Archives Journals. (2010, July 13). Low vitamin D levels associated with cognitive decline. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2010/07/100712162554.htm
JAMA and Archives Journals. "Low vitamin D levels associated with cognitive decline." ScienceDaily. www.sciencedaily.com/releases/2010/07/100712162554.htm (accessed July 28, 2014).

Share This




More Health & Medicine News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional African Dishes Teach Healthy Eating

Traditional African Dishes Teach Healthy Eating

AP (July 28, 2014) Classes are being offered nationwide to encourage African Americans to learn about cooking fresh foods based on traditional African cuisine. The program is trying to combat obesity, heart disease and other ailments often linked to diet. (July 28) Video provided by AP
Powered by NewsLook.com
West Africa Gripped by Deadly Ebola Outbreak

West Africa Gripped by Deadly Ebola Outbreak

AFP (July 28, 2014) The worst-ever outbreak of the deadly Ebola epidemic grips west Africa, killing hundreds. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Trees Could Save More Than 850 Lives Each Year

Trees Could Save More Than 850 Lives Each Year

Newsy (July 27, 2014) A national study conducted by the USDA Forest Service found that trees collectively save more than 850 lives on an annual basis. Video provided by Newsy
Powered by NewsLook.com
Google's Next Frontier: The Human Body

Google's Next Frontier: The Human Body

Newsy (July 27, 2014) Google is collecting genetic and molecular information to paint a picture of the perfectly healthy human. Video provided by Newsy
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:
from the past week

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