Posts tagged vitamin d
Articles and news from the latest research reports.
Vitamin D Tied to Women’s Cognitive Performance
Two new studies appearing in the Journals of Gerontology Series A: Biological Sciences and Medical Sciences show that vitamin D may be a vital component for the cognitive health of women as they age.
Higher vitamin D dietary intake is associated with a lower risk of developing Alzheimer’s disease, according to research conducted by a team led by Cedric Annweiler, MD, PhD, at the Angers University Hospital in France.
Similarly, investigators led by Yelena Slinin, MD, MS, at the VA Medical Center in Minneapolis found that low vitamin D levels among older women are associated with higher odds of global cognitive impairment and a higher risk of global cognitive decline.
Slinin’s group based its analysis on 6,257 community-dwelling older women who had vitamin D levels measured during the Study of Osteopathic Fractures and whose cognitive function was tested by the Mini-Mental State Examination and/or Trail Making Test Part B.
Very low levels of vitamin D (less than 10 nanograms per milliliter of blood serum) among older women were associated with higher odds of global cognitive impairment at baseline, and low vitamin D levels (less than 20 nanograms per milliliter) among cognitively-impaired women were associated with a higher risk of incident global cognitive decline, as measured by performance on the Mini-Mental State Examination.
Annweieler’s team’s findings were based on data from 498 community-dwelling women who participated in the Toulouse cohort of the Epidemiology of Osteoporosis study.
Among this population, women who developed Alzheimer’s disease had lower baseline vitamin D intakes (an average of 50.3 micrograms per week) than those who developed other dementias (an average of 63.6 micrograms per week) or no dementia at all (an average of 59.0 micrograms per week).
These reports follow an article published in the Journals of Gerontology Series A earlier this year that found that both men and women who don’t get enough vitamin D — either from diet, supplements, or sun exposure — may be at increased risk of developing mobility limitations and disability.
(Photo Credit: Paul Burns / Getty Images)
Low vitamin D levels associated with longevity
Low levels of vitamin D may be associated with longevity, according to a study involving middle-aged children of people in their 90s published in CMAJ (Canadian Medical Association Journal).
"We found that familial longevity was associated with lower levels of vitamin D and a lower frequency of allelic variation in the CYP2R1 gene, which was associated with higher levels of vitamin D," writes Dr. Diana van Heemst, Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, the Netherlands, with coauthors.
Previous studies have shown that low levels of vitamin D are associated with increased rates of death, heart disease, diabetes, cancer, allergies, mental illness and other afflictions. However, it is not known whether low levels are the cause of these diseases or if they are a consequence.
To determine whether there was an association between vitamin D levels and longevity, Dutch researchers looked at data from 380 white families with at least 2 siblings over age 90 (89 years or older for men and 91 year or older for women) in the Leiden Longevity Study. The study involved the siblings, their offspring and their offsprings’ partners for a total of 1038 offspring and 461 controls. The children of the nonagenarians were included because it is difficult to include controls for the older age group. The partners were included because they were of a similar age and shared similar environmental factors that might influence vitamin D levels.
The researchers measured levels of 25(OH) vitamin D and categorized levels by month as they varied according to season. Tanning bed use, which can affect vitamin D levels, was categorized as never, 1 times per year and 6 times per year. The researchers controlled for age, sex, BMI (body mass index), time of year, vitamin supplementation and kidney function, all factors that can influence vitamin D levels. They also looked at the influence of genetic variation in 3 genes associated with vitamin D levels.
"We found that the offspring of nonagenarians who had at least 1 nonagenarian sibling had lower levels of vitamin D than controls, independent of possible confounding factors and SNPs [single nucleotide polymorphisms] associated with vitamin D levels," write the authors. "We also found that the offspring had a lower frequency of common genetic variants in the CYP2R1 gene; a common genetic variant of this gene predisposes people to high vitamin D levels.
These findings support an association between low vitamin D levels and familial longevity.” They postulate that offspring of nonagenarians might have more of a protein that is hypothesized to be an “aging suppressor” protein. More research is needed to understand the link between lower vitamin D levels, genetic variants and familial longevity.
(Source: eurekalert.org)
Vitamin D deficiency during pregnancy could hinder babies’ brain development, impeding their mental and motor skills, a new study suggests.
Researchers in Spain measured the level of vitamin D in the blood of almost 2,000 women in their first or second trimester of pregnancy and evaluated the mental and motor abilities of their babies at about 14 months of age. The investigators found that children of vitamin D-deficient mothers scored lower than those whose mothers had adequate levels of the sunshine vitamin.
"These differences in the mental and psychomotor development scores do not likely make any difference at the individual level, but might have an important impact at the population level," said study lead author Dr. Eva Morales, a medical epidemiologist in the Center for Research in Environmental Epidemiology in Barcelona.
Overall, lower scores in these tests could lead to lower IQs among children, Morales added. The study was published online Sept. 17 and in the October print issue of the journal Pediatrics.
New link found between MS treatment and vitamin D
July 30, 2012
(Medical Xpress) — A new study by researchers at the Menzies Research Institute Tasmania (Menzies) suggests that one of the main treatments for multiple sclerosis (MS) may also increase the amount of vitamin D patients receive from sun exposure.
More people suffer with MS per capita in Tasmania than in any other state in Australia. There is currently no cure, but treatments are available to ease some of the symptoms.
This observational study published in the prestigious journal Neurology found that patients taking one of the most common treatments for MS, interferon-beta, had higher vitamin D levels than those not on this treatment or those using other forms of treatment for MS.
Around 60 per cent of MS patients with the relapsing-remitting form of MS are treated with interferon-beta. It is derived from a naturally-occurring component of the human immune system and has been found to reduce the frequency of relapse and other specific symptoms of MS.
Despite being a front-line treatment in MS, how interferon-beta actually works in MS is unclear, though it is thought to act by affecting the immune system.
The study used data from the MS Longitudinal Study, from 2002-2005, and this analysis used data from 178 persons with MS living in southern Tasmania.
Menzies researchers Dr. Niall Stewart and Dr. Steve Simpson, Jr. were co-first authors on the paper. Dr. Simpson says the findings suggest that part of the therapeutic effects of interferon-beta on relapse in MS may be through its effects on vitamin D, since vitamin D has the ability to reduce inflammatory pathways in the immune system.
“Not only did we find that persons taking interferon-beta had higher vitamin D levels than those not taking it, we also found that this increase in vitamin D was due to an enhancement of the association between sun and vitamin D, with persons on interferon-beta having nearly three-times as much vitamin D from similar amounts of sun exposure to those not taking interferon-beta,” Dr. Simpson said.
“We have previously shown persons with MS with higher vitamin D levels had lower numbers of relapses. In this analysis, however, we found that vitamin D was only associated with reduced risk of relapse among those using interferon-beta.
“Interestingly, the reciprocal was also true, with interferon-beta only associated with reduced risk of relapse among those with higher levels of vitamin D,” Dr. Simpson said.
Senior author, Professor Bruce Taylor, says the new findings have the potential to markedly affect clinical practice in the treatment of MS, but cautions that more research is required.
“This study adds to the growing body of research into MS, but before we can apply these findings to MS treatment practice, clinical trials must be done to prove these associations. Menzies is planning to undertake such a trial in the future,” Professor Taylor said.
“This study does provide further support for persons with MS to periodically have their vitamin D measured, particularly in winter, and if they are deficient, to seek the advice of their physician as to whether supplementation is appropriate for them.”
Provided by University of Tasmania
Source: medicalxpress.com