Senior Citizens with Highest Levels of Vitamin D
Show Most Vitality as They Age
New study does say participants with better
physical function may have higher vitamin D simply because they go
outside more often
April 26, 2010 We are living longer than ever,
but increasingly senior citizens are learning that the quantity of years
is not as important as the quality. A myriad of consequences result from
aging and among the most common are painful bone and joint diseases that
make simple movement a challenge. New research was released yesterday
showing seniors with higher levels of vitamin D demonstrate more youth
and vitality as they enjoy longer life spans.
A limited number of studies have pointed to the
possibility that optimal intake of vitamin D (the "sunshine" vitamin)
might help keep our muscles strong and preserve physical function.
Review of 28 studies finds the vitamin associated
with a substantial decrease in cardiovascular disease, type 2 diabetes
and metabolic syndrome for seniors and middle aged
Researchers also urging close monitoring of elderly
with hypertension during weather extremes; second study says thinking
ability varies with blood pressure
To help understand this diet-health association,
Dr. Denise Houston from the Sticht Center on Aging at Wake Forest
University and her collaborators studied the relationship between
vitamin D status and physical function in a group of relatively healthy
seniors living in Memphis, TN and Pittsburgh, PA.
Their results were presented on Sunday, April 25 as
part of the scientific program of the American Society for Nutrition,
composed of the world's leading nutrition researchers, at the
Experimental Biology 2010 meeting in Anaheim.
This study was part of the Health, Aging, and Body
Composition (Health ABC) study initially designed to assess the
associations among body composition, long-term health conditions, and
mobility in older adults.
For Houston's segment of the investigation, she
studied 2788 seniors (mean age: 75 years) for 4 years. At the beginning
of the study, they assessed vitamin D status by analyzing each person's
blood for 25-hydroxyvitamin D, a precursor for activated vitamin D.
At baseline and then 2 and 4 years later, the
research team then determined whether circulating 25-hydroxyvitamin D
was related to the participants' physical function. Specifically, they
looked at how quickly each participant could walk a short distance (6
meters) and rise from a chair five times as well as maintain his or her
balance in progressively more challenging positions.
Each participant
was also put through a battery of tests assessing endurance and
strength.
When the results were tabulated, participants with
the highest levels of 25-hydroxyvitamin D had better physical function.
And, although physical function declined over the course of the study,
it remained significantly higher among those with the highest vitamin D
levels at the beginning of the study compared to those with the lowest
vitamin D levels.
The scientists were not surprised to learn that, in
general, vitamin D consumption was very low in this group of otherwise
healthy seniors. In fact, more than 90% of them consumed less vitamin D
than currently recommended, and many were relying on dietary
supplements.
The good news: higher circulating 25-hydroxyvitamin
D is related to better physical function in seniors. But it's impossible
to tell from this type of research whether increasing vitamin D intake
will actually lead to stronger muscles and preserve physical function.
This is partly due to the fact that our bodies can
make vitamin D if they get enough sunlight. So, it is possible that the
participants with better physical function had higher vitamin D status
simply because they were able to go outside more often. Indeed, the
ominous "chicken-or-the-egg" question can only be answered by carefully
controlled clinical intervention trials.
Nonetheless, it is possible that getting more
vitamin D from foods (like fortified milk and oily fish) or supplements
will help maintain youth and vitality as we enjoy longer lifespans.
As Houston points out: "Current dietary
recommendations are based primarily on vitamin D's effects on bone
health. It is possible that higher amounts of vitamin D are needed for
the preservation of muscle strength and physical function as well as
other health conditions. However, clinical trials are needed to
definitively determine whether increasing 25-hydroxyvitamin D
concentrations through diet or supplements has an effect on these
non-traditional outcomes."
Will vitamin D research lead us to The Fountain of
Youth?
Probably not. But paying attention to how much vitamin D we get
is likely important at every age and will help enhance the "quality"
component of life as we enter our senior years.
Co-authors of the study included Dr. Denise Houston
(Wake Forest University, Winston Salem, NC); Dr. Janet Tooze (Wake
Forest University); Rebecca Neiberg (Wake Forest University), Dr. Kyla
Shea (Wake Forest University), Dr. Dorothy Hausman (University of
Georgia, Athens, GA), Dr. Mary Ann Johnson (University of Georgia), Dr.
Jane Cauley (University of Pittsburgh, Pittsburgh, PA), Dr. Doug Bauer
(University of California, San Francisco, CA), Dr. Frances Tylavsky
(University of Tennessee, Memphis, TN), Dr. Marjolein Visser (VU
University, Amsterdam, Netherlands), Dr. Eleanor Simonsick (National
Institute on Aging, Baltimore, MD), Dr. Tamara Harris (National
Institute on Aging), and Dr. Stephen Kritchevsky (Wake Forest
University).
April 26, 2010 We are living longer than ever,
but increasingly senior citizens are learning that the quantity of years
is not as important as the quality. A myriad of consequences result from
aging and among the most common are painful bone and joint diseases that
make simple movement a challenge. New research was released yesterday
showing seniors with higher levels of vitamin D demonstrate more youth
and vitality as they enjoy longer life spans.
