Mounting Evidence that Low Levels of Vitamin D
Increase Death Risk for Older People
Death rates from any cause and from cardiovascular
causes were higher with low vitamin D
June
23, 2008 Vitamin D is something we used to not worry about. Most of us
got plenty from the sun and being a little low was only a worry that
your bones may not be the strongest. Mostly, however, we thought that
was something our mothers said just to get us to drink more milk. There
is, however, mounting evidence that vitamin D is far more important that
many of us thought.
The latest study of people with an average age of
62 finds individuals with lower blood levels of vitamin D appear to have
an increased risk of death overall, as well as from cardiovascular
causes, according to a report in the June 23 issue of Archives of
Internal Medicine, one of the JAMA/Archives journals.
A recent consensus panel estimated that about 50
percent to 60 percent of older individuals in North America and the rest
of the world do not have satisfactory vitamin D status, and the
situation is similar for younger individuals, according to background
information in the article.
Blood levels of 25-hydroxyvitamin D, a measure of
blood vitamin D levels, lower than 20 to 30 nanograms per milliliter
have been associated with falls, fractures, cancer, immune dysfunction,
cardiovascular disease and hypertension.
These effects are thought to be mediated by the
compound 1,25-dihydroxyvitamin D, which is produced by the body and also
converted from 25-hydroxyvitamin D.
The 25-hydroxy vitamin D test is the most accurate
measure of the amount of vitamin D in the body. In the kidney,
25-hydroxy vitamin D changes into an active form called 1,25-dihydroxy
vitamin D.
Harald Dobnig, M.D., of Medical University of Graz,
Austria, and colleagues studied 25-hydroxyvitamin D and
1,25-dihydroxyvitamin D levels in 3,258 consecutive patients (average
age 62 years) who were scheduled for coronary angiography testing at a
single medical center between 1997 and 2000.
During about 7.7 years of follow-up, 737 (22.6
percent) of participants died, including 463 (62.8 percent) who died of
cardiovascular causes.
Death rates from any cause and from cardiovascular
causes were higher among individuals in the lower one-half of
25-hydroxyvitamin D levels and the lowest one-fourth of
1,25-dihydroxyvitamin D levels.
These associations remained when the researchers
accounted for other factors, including coronary artery disease, physical
activity level and co-occurring diseases.
Low 25-hydroxyvitamin D levels also were correlated
with markers of inflammation such as C-reactive protein, as well as
signs of oxidative (oxygen-related) damage to cells, the authors note.
Apart from the proved effects that vitamin D has
on bone metabolism and neuromuscular function, appropriate serum levels
(that may also be higher than in the present investigation) are
associated with a decrease in mortality, they conclude.
Although not proved, it seems possible that at
least part of this effect may be due to lowering of a risk profile
promoting atherosclerosis [narrowing of the arteries] and preventing
cardiovascular end points.
Based on the findings of this study, a serum
25-hydroxy-vitamin D level of 20 nanograms per milliliter or higher may
be advised for maintaining general health.
Editor's Note: The LURIC study has received
unrestricted grants from Sanofi-Aventis, Roche, Dade Behring and
AstraZeneca.
June
23, 2008 Vitamin D is something we used to not worry about. Most of us
got plenty from the sun and being a little low was only a worry that
your bones may not be the strongest. Mostly, however, we thought that
was something our mothers said just to get us to drink more milk. There
is, however, mounting evidence that vitamin D is far more important that
many of us thought. 
Treatments with activated vitamin D prevented heart
muscle cells from growing bigger