2011 — New research linking low vitamin D levels with deaths
from heart disease and other causes bolsters mounting evidence about
the "sunshine" vitamin's role in good health.
Patients with the lowest blood levels of vitamin D were about two
times more likely to die from any cause during the next eight years
than those with the highest levels, the study found. The link with
heart-related deaths was particularly strong in those with low
vitamin D levels were related to poor physical activity.
Experts say the results shouldn't be seen as a reason to start
popping vitamin D pills or to spend hours in the sun, which is the
main source for vitamin D.
deficiency increases the risk of diseases.
Low vitamin D levels could reflect age, lack of physical activity
and other lifestyle factors that also affect health, said American
Heart Association spokeswoman Alice Lichtenstein, director of the
Cardiovascular Nutrition Laboratory at Tufts University.
Still, she said the study is an important addition to an emerging
area of research.
"This is something that should not be ignored," Lichtenstein
The study led by Austrian researchers involved 3,258 men and
women in southwest Germany. Participants were aged 62 on average,
most with heart disease, whose vitamin D levels were checked in
weekly blood tests. During roughly eight years of follow-up,
died, including 463 from heart-related problems.
According to one of the vitamin tests they used, there were 307
deaths in patients with the lowest levels, versus 103 deaths in
those with the highest levels. Counting age, physical activity and
other factors, the researchers calculated that deaths from all
causes were about twice as common in patients in the lowest-level
The study's lead author, Dr. Harald Dobnig of the Medical
University of Graz in Austria, said the results don't prove that low
levels of vitamin D are harmful "but the evidence is just becoming
overwhelming at this point."
Scientists used to think that the only role of vitamin D was to
prevent rickets and strengthen bones, Dobnig said.
"Now we are beginning to realize that there is much more into
it," he said
Exactly how low vitamin D levels might contribute to heart
problems and deaths from other illnesses is uncertain, although it
is has been shown to help regulate the body's disease-fighting
immune system, he said.
Earlier this month, the same journal included research led by
Harvard scientists linking low vitamin D levels with heart attacks.
And previous research has linked low vitamin D with high blood
pressure, diabetes and obesity, which all can contribute to heart
The new research "provides the strongest evidence to date for a
link between vitamin D deficiency and cardiovascular mortality,"
said Dr. Edward Giovannucci of the Harvard study of 18,225 men.
Low vitamin D levels also have been linked with several kinds of
cancer and some researchers believe the vitamin could even be used
to help prevent malignancies.
It has been estimated that at least 50 percent of older adults
worldwide have low vitamin D levels, and the problem is also thought
to affect substantial numbers of younger people. Possible reasons
include decreased outdoor activities, air pollution and, as people
age, a decline in the skin's ability to produce vitamin D from
ultraviolet rays, the study authors said.
Some doctors believe overuse of sunscreen lotions has
contributed, and say just 10 to 15 minutes daily in the sun without
sunscreen is safe and enough to ensure adequate vitamin D, although
there's no consensus on that.
Diet sources include fortified milk, which generally contains 100
international units of vitamin D per cup, and fatty fish _ 3 ounces
of canned tuna has 200 units.
The Institute of Medicine's current vitamin D recommendations are
200 units daily for children and adults up to age 50, and 400 to 600
units for older adults. But some doctors believe these amounts are
far too low.