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Amanda Jekowsky , American College of
Cardiology, 202-375-6645, ajekowsk@acc.org
December
1, 2008
Lack of Vitamin D could spell heart
trouble
Researchers issue recommendations to screen for
and treat Vitamin D deficiency
Vitamin D deficiency—which is traditionally
associated with bone and muscle weakness—may also increase
the risk of cardiovascular disease (CVD). A growing body of
evidence links low 25-hydroxyvitamin D levels to common CVD
risk factors such as hypertension, obesity and diabetes, as
well as major cardiovascular events including stroke and congestive
heart failure.
In their review article, published in the December,
9, 2008, issue of the Journal of the American College
of Cardiology (JACC), the authors issue practical recommendations
to screen for and treat low vitamin D levels, especially in
patients with risk factors for heart disease or diabetes.
“Vitamin D deficiency is an unrecognized,
emerging cardiovascular risk factor, which should be screened
for and treated,” said James H. O’Keefe, M.D.,
cardiologist and director of Preventive Cardiology at the
Mid America Heart Institute, Kansas City, MO. “Vitamin
D is easy to assess, and supplementation is simple, safe and
inexpensive.”
It is estimated that up to half of U.S. adults and 30 percent
of children and teenagers have vitamin D deficiency, which
is defined as a 25(OH)D level of <20ng/ml. Low vitamin
D levels activate the renin-angiostensin-aldosterone system
and, in doing so, predispose patients to hypertension and
a stiffening and thickening of the heart and blood vessels.
Vitamin D deficiency also alters hormone levels and immune
function, which can increase the risk of diabetes, a major
contributor to CVD.
Recent data from the Framingham Heart Study
suggest patients with vitamin D levels below 15 ng/ml were
twice as likely to experience a heart attack, stroke or other
CV event within the next five years compared to those with
higher levels. This risk remained even when researchers adjusted
for traditional CV risk factors.
“Restoring vitamin D levels to normal
is important in maintaining good musculoskeletal health, and
it may also improve heart health and prognosis,” said
Dr. O’Keefe. “We need large randomized controlled
trials to determine whether or not vitamin D supplementation
can actually reduce future heart disease and deaths.”
Vitamin D Basics
Vitamin D deficiency is more prevalent than
once thought, and greater attention to its treatment is warranted,
according to Dr. O’Keefe. Although most of the body’s
vitamin D requirements can come from sun exposure, indoor
lifestyles and use of sunscreen, which eliminates 99 percent
of vitamin D synthesis by the skin, means many people aren’t
producing enough.
“We are outside less than we used to be,
and older adults and people who are overweight or obese are
less efficient at making vitamin D in response to sunlight,”
said Dr. O’Keefe. “A little bit of sunshine is
a good thing, but the use of sunscreen to guard against skin
cancer is important if you plan to be outside for more than
15 to 30 of intense sunlight exposure.”
Vitamin D can also be consumed through supplements
and food intake. Natural food sources of vitamin D include
salmon, sardines, cod liver oil, and vitamin D-fortified foods
including milk and some cereals.
Major risk factors for vitamin D deficiency
include: older age, darkly pigmented skin, increased distance
from the equator, winter season, smoking, obesity, renal or
liver disease and certain medications.
Treating Vitamin D Deficiency
In the absence of clinical guidelines, the authors
outline specific recommendations for restoring and maintaining
optimal vitamin D levels in CV patients. These patients should
initially be treated with 50,000 IU of vitamin D2 or D3 once
weekly for 8 to 12 weeks. Maintenance therapy should be continued
using one of the following strategies:
- 50,000 IU vitamin D2 or D3every 2 weeks;
- 1,000 to 2,000 IU vitamin D3 daily;
- Sunlight exposure for 10 minutes for Caucasian patients
(longer for people with increased skin pigmentation) between
the hours of 10 a.m. to 3 p.m.
Vitamin D supplements appear to be safe. In rare cases, vitamin
D toxicity (causing high calcium levels and kidney stones)
is possible, but only when taking in excess of 20,000 units
a day.
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The American College of Cardiology is leading the way to optimal
cardiovascular care and disease prevention. The College is
a 36,000-member nonprofit medical society and bestows the
credential Fellow of the American College of Cardiology upon
physicians who meet its stringent qualifications. The College
is a leader in the formulation of health policy, standards
and guidelines, and is a staunch supporter of cardiovascular
research. The ACC provides professional education and operates
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quality care. More information about the association is available
online at www.acc.org .
The American College of Cardiology (ACC) provides these news
reports of clinical studies published in the Journal of
the American College of Cardiology as a service to physicians,
the media, the public and other interested parties. However,
statements or opinions expressed in these reports reflect
the view of the author(s) and do not represent official policy
of the ACC unless stated so.
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