Scientists Find New Way to Detect, Treat Vitamin D
Deficiency that Threatens Heart
Lack of vitamin D spells heart trouble as well as
a lot of other ailments
Dec. 2, 2008 There is little doubt left that a
deficiency of vitamin D is a warning sign for cardiovascular disease
as well as many other ailments from bone weakness to Parkinsons
disease. A new review of available research has produced practical
recommendations for detecting and treating this potentially critical
problem.
Related Stories
Vitamin D, once linked to
only bone diseases such as rickets and osteoporosis, is now recognized as a
major player in contributing to overall human health - read story below the
main news report. Click
Vitamin D deficiency is most often associated with
bone and muscle weakness. In the review article, published in the
December, 9, 2008, issue of the Journal of the American College of
Cardiology (JACC), the authors point to a growing body of evidence links
low 25-hydroxyvitamin D levels to common cardiovascular disease (CVD)
risk factors such as hypertension, obesity and diabetes, as well as
major cardiovascular events including stroke and congestive heart
failure.
"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 vitamin D level of less than 20 ng/ml (20 nanograms per
milliliter).
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.
'Let the sunshine in' to protect your
heart this winter
Nov. 17, 2008 The temperature might not
be the only thing plummeting this winter. Many people also will
experience a decrease in their vitamin D levels, which can play
a role in heart disease, according to a new review article in
Circulation.
Vitamin D deficiency results in part from
reduced exposure to sunlight, which is common during cold
weather months when days are shorter and more time is spent
indoors.
"Chronic vitamin D deficiency may be a
culprit in heart disease, high blood pressure and metabolic
syndrome," said Sue Penckofer, PhD, RN, study author and
professor, Marcella Niehoff School of Nursing, Loyola University
Chicago.
The review article cited a number of
studies that linked vitamin D deficiency to heart disease. These
studies found rates of severe disease or death may be 30 to 50
percent higher among sun-deprived individuals with heart
disease.
Penckofer and colleagues concluded that
diet alone is not sufficient to manage vitamin D levels.
Treatment options to correct this level, such as vitamin D2 or
D3, may decrease the risk of severe disease or death from
cardiovascular disorders. The preferred range in the body is 30
- 60 ng/mL of 25(OH) vitamin D.
"Most physicians do not routinely test for
vitamin D deficiency," said Penckofer. "However, most experts
would agree that adults at risk for heart disease and others who
experience fatigue joint pain or depression should have their
vitamin D levels measured."
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:
1. 50,000 IU vitamin D2 or D3 every 2 weeks;
2. 1,000 to 2,000 IU vitamin D3 daily;
3. 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.
Background Information by Source
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 national registries for the measurement and improvement of
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.
Vitamin D a Key Player in Overall
Health of Several
Body Organs, says UC Riverside Biochemist
Oct. 9, 2008 Essential for life in higher
animals, vitamin D, once linked to only bone diseases such as rickets
and osteoporosis, is now recognized as a major player in contributing to
overall human health, emphasizes UC Riverside's
Anthony Norman, an international expert on vitamin D.
In a paper published in the August issue of the
American Journal of Clinical Nutrition, Norman identifies vitamin
D's potential for contributions to good health in the adaptive and
innate immune systems, the secretion and regulation of insulin by the
pancreas, the heart and blood pressure regulation, muscle strength and
brain activity. In addition, access to adequate amounts of vitamin D is
believed to be beneficial towards reducing the risk of cancer.
Norman also lists 36 organ tissues in the body
whose cells respond biologically to vitamin D. The list includes bone
marrow, breast, colon, intestine, kidney, lung, prostate, retina, skin,
stomach and the uterus.
According to Norman, deficiency of vitamin D can
impact all 36 organs. Already, vitamin D deficiency is associated with
muscle strength decrease, high risk for falls, and increased risk for
colorectal, prostate and breast and other major cancers.
"It is becoming increasingly clear to researchers
in the field that vitamin D is strongly linked to several diseases,"
said Norman, a distinguished professor emeritus of biochemistry and of
biomedical sciences who has worked on vitamin D for more than 45 years.
"Its biological sphere of influence is much broader than we originally
thought. The nutritional guidelines for vitamin D intake must be
carefully reevaluated to determine the adequate intake, balancing
sunlight exposure with dietary intake, to achieve good health by
involving all 36 target organs."
Vitamin D is synthesized in the body in a series of
steps. First, sunlight's ultraviolet rays act on a precursor compound in
skin. When skin is exposed to sunlight, a sterol present in dermal
tissue is converted to vitamin D, which, in turn, is metabolized in the
liver and kidneys to form a hormone. It was Norman's laboratory that
discovered, in 1967, that vitamin D is converted into a steroid hormone
by the body.
The recommended daily intake of vitamin D is 200
international units (IU) for people up to 50 years old. The recommended
daily intake of vitamin D is 400 IU for people 51 to 70 years old and
600 IU for people over 70 years old. Norman's recommendation for all
adults is to have an average daily intake of at least 2000 IU.
"To optimize good health you must have enough
vitamin D," he said. "Vitamin D deficiency is also especially of concern
in third world countries that have poor nutritional practices and
religious customs that require the body to be covered from head to toe.
Ideally, to achieve the widest frequency of good health by population,
we need to have 90 percent of the people with adequate amounts of
vitamin D."
About half of the elderly in North America and
two-thirds of the rest of the world are not getting enough vitamin D to
maintain healthy bone density, lower their risks for fracture and
improve tooth attachment.
"There needs to be a sea change by various
governmental agencies in terms of the advice they present to citizens
about how much vitamin D should be taken," Norman said. "The tendencies
of people to live in cities where tall buildings block adequate sunlight
from reaching the ground, to spend most of their time indoors, to use
synthetic sunscreens that block ultraviolet rays, and to live in
geographical regions of the world that do not receive adequate sunlight
all contribute to the inability of the skin to biosynthesize sufficient
amounts of vitamin D."
Found in minute amounts in food, vitamins are
organic substances that higher forms of animals need to grow and sustain
normal health. Vitamins, however, are not synthesized in sufficient
amounts to meet bodily needs. Therefore, the body must acquire them
through diet or in the form of supplements.
Because it is found in very few foods naturally,
milk and other foods (often orange juice) are fortified with vitamin D.
While deficiency of vitamin D impacts health
negatively, ingestion of extremely high doses of vitamin D can cause
hypercalcemia, a condition in which the blood's calcium level is above
normal. The highest daily 'safe' dose of vitamin D is 10,000 IU.
"More than ever we need to increase the amount of
research on vitamin D, with more funding from government agencies and
pharmaceutical companies, to meet the challenge of preserving or
improving the health of everyone on the planet," Norman said.
Keep up with the latest news for senior citizens, baby
boomers
Dec. 2, 2008 There is little doubt left that a
deficiency of vitamin D is a warning sign for cardiovascular disease
as well as many other ailments from bone weakness to Parkinsons
disease. A new review of available research has produced practical
recommendations for detecting and treating this potentially critical
problem.
Oct. 9, 2008 Essential for life in higher
animals, vitamin D, once linked to only bone diseases such as rickets
and osteoporosis, is now recognized as a major player in contributing to
overall human health, emphasizes UC Riverside's