Vitamin D May Lower Heart Disease Risk
Studies Suggest That Correcting Vitamin D Deficiency Improves Heart Health
March 15, 2010 (Atlanta) -- If you have low vitamin D levels, correcting the
deficiency may reduce the risk for heart disease, new research
The studies build on the researchers' previous work linking low levels of
vitamin D to an
increased risk for heart disease.
The researchers, from the Intermountain Medical Center Heart Institute in
Murray, Utah, presented the new studies at the American College of Cardiology's
59th annual scientific session.
Vitamin D vs. Heart Disease: Study Details
The first study involved more than 9,400 patients whose blood tests revealed
low vitamin D levels during a routine trip to the doctor. Their average
vitamin D level was 19.3 nanograms per milliliter; levels of 30 are generally
considered "normal," according to J. Brent Muhlestein, MD, the Institute's
director of cardiovascular research.
At their next follow-up visit, about half had raised their vitamin D levels
to above 30 nanograms per milliliter.
Compared with patients whose vitamin D levels were still low, patients who
raised their vitamin D levels were 33% less likely to have a heart attack, 20% less likely
to develop heart failure, and 30% less
likely to die over an average follow-up period of one year.
In the second study, the researchers placed more than 41,000 patients into
three categories based on their levels of vitamin D -- normal, moderate
deficiency, and severe deficiency. Then they combed their medical records to
see who had been diagnosed with heart disease or stroke.
As expected, patients with severe deficiency were most likely to have been
diagnosed with heart disease or stroke, Muhlestein tells WebMD.
Then the researchers put all the information into a computer algorithm to
see if there is an optimal level of vitamin D when it comes to heart disease
"While normal has generally been considered to be 30, some people have
suggested 40 or 50 is better.
"What we found is that people who increased their vitamin D blood level to
43 nanograms per milliliter had the lowest rates of heart disease and stroke.
But increasing it beyond that, say to 60 or 70, offered no greater benefit," he
Vitamin D Findings May Change Some Doctors' Practices
Although doctors say better-designed studies showing that vitamin D
supplements help are needed, Muhlestein says the results of this research will
already change the way he treats his patients.
"There is enough information here for me to start treatment based on these
findings," he says.
Treatment options in this case are simple, starting with a blood test to
determine a patient's vitamin D level. If low levels are detected, Muhlestein
recommends that men and women boost their vitamin D levels by taking vitamin
supplements and briefly exposing skin to the sun's vitamin
D-producing ultraviolet light.
The Institute of Medicine suggests that an adequate daily intake of vitamin
D is between 200 and 400 international units (IU) for children and adults up to
age 70. But increasing vitamin D intake by 1,000 to 5,000 IU a day may be
appropriate, depending on a patient's health and genetic risk, Muhlestein