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Nutrition, Vitamins & Supplements for Seniors
Adequate Vitamin D3 Could Prevent 600,000 Breast,
Colon Cancer Cases
Vitamin D3 is obtained through diet, supplements and sunlight
 Aug. 22, 2007 – Vitamin D continues to win praise
for its contribution to better health. This time it is a study that says
600,000 cases of breast and colon cancer could be prevented around the
globe – 150,000 in the U.S. - each year if more people reached the
recommended levels of vitamin D3.
Cedric F. Garland, Dr.P.H., cancer prevention
specialist at the Moores Cancer Center at the University of California,
San Diego (UCSD) and colleagues estimate that 250,000 cases of
colorectal cancer and 350,000 cases of breast cancer could be prevented
worldwide by increasing intake of vitamin D3, particularly in countries
north of the equator.
Vitamin D3 is available through diet, supplements
and exposure of the skin to sunlight.
“For the first time, we are saying that 600,000
cases of breast and colorectal cancer could be prevented each year
worldwide, including nearly 150,000 in the United States alone,” said
study co-author Garland. The paper, which looks at the dose-response
relationship between vitamin D and cancer, will be published in the
August edition of the journal Nutrition Reviews.
The study combined data from surveys of serum
vitamin D levels during winter from 15 countries. It is the first such
study to look at satellite measurements of sunshine and cloud cover in
countries where actual blood serum levels of vitamin D3 had also been
determined. The data were then applied to 177 countries to estimate the
average serum level of a vitamin D metabolite of people living there.
The data revealed an inverse association of serum
vitamin D with risk of colorectal and breast cancer.
The protective effect began at levels ranging from
24 to 32 nanograms per milliliter of 25-hydroxyvitamin D concentration
in the serum. The 25-hydroxyvitamin D level is the main indicator of
vitamin D status.
The late winter average 25-hydroxyvitamin D in the
US is about 15-18 ng/ml. The researchers maintain that increasing
vitamin D levels in populations, particularly those in northern
climates, has the potential to both prevent and possibly serve as an
adjunct to existing treatments for cancer.
The work builds on previous studies by Garland and
colleagues (Journal of Steroid Biochemistry and Molecular, February
2007) which found that raising the serum 25(OH)D levels to 55 ng/mL was
optimal for cancer prevention.
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More About Vitamin D |
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Vitamin D is found in numerous dietary sources
such as fish, eggs, fortified milk, and cod liver oil. The sun
is also a significant contributor to our daily production of
vitamin D, and as little as 10 minutes of exposure is thought to
be enough to prevent deficiencies.
The term "vitamin D" refers to several different
forms of this vitamin. Two forms are important in humans:
ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Vitamin D2 is synthesized by plants. Vitamin D3 is synthesized
by humans in the skin when it is exposed to ultraviolet-B (UVB)
rays from sunlight or the diet.
The major biologic function of vitamin D is to
maintain normal blood levels of calcium and phosphorus. Vitamin
D aids in the absorption of calcium, helping to form and
maintain strong bones.
Recently, research also suggests vitamin D may
provide protection from osteoporosis, hypertension, cancer, and
several autoimmune diseases.
>>
More at National Institutes of Health’s
MedlinePLUS |
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This is the first study to recommend optimal
vitamin D serum levels which, Garland said, are high enough to provide
the needed benefit but which have been found by other scientists to be
low enough to avoid health risks.
“This could be best achieved with a combination of
diet, supplements and short intervals – 10 or 15 minutes a day – in the
sun,” said Garland. It could be less for very fair-skinned individuals.
He went on to say that “the appropriate dose of vitamin D in order to
reach this level, could be very little in a lifeguard in Southern
California… or quite a lot for someone in Northern Europe who tends to
remain indoors most of the year.”
The serum level recommended by the study would
correspond to intake of 2000 International Units per day of vitamin D3
for a meaningful reduction in colorectal cancer. The researchers
recommend 2000 IU/day, plus, when weather allows, a few minutes in the
sun with at least 40% of the skin exposed, for a meaningful reduction in
breast cancer incidence, unless the individual has a history of skin
cancer or a photosensitivity disease.
Garland also recommends moderate sun exposure and
use of clothing and a hat when in the sun longer than 15 minutes.
This paper used worldwide data only recently
available through a new tool called GLOBOCAN, developed by the World
Health Organization’s International Agency for Research on Cancer.
GLOBOCAN is a database of cancer incidence,
mortality and prevalence for 177 countries. Previous studies from this
core group have shown an association between higher levels of vitamin D3
or markers of vitamin D status and lower risk of cancers of the breast,
colon, ovary and kidney.
The researchers underscore their call for prompt
public health action to increase intake of vitamin D3 as an inexpensive
tool for prevention of diseases that claim nearly one million lives each
year world wide.
“The message is, depending on where you live, you
may need to consider taking in considerably higher levels of vitamin D3
than those currently recommended,” said Garland. “I’d recommend
discussing vitamin D needs with a health care professional, who may
order and interpret a simple blood test for a vitamin D metabolite
[25(OH)D], and provide a dosage recommendation that’s appropriate for
the individual’s needs.”
Editor’s Notes:
The study was co-authored by Cedric F. Garland, Dr.
P.H., Sharif B. Mohr, M.P.H., Edward D. Gorham, M.P.H., Ph.D., and Frank
C. Garland, Ph.D., of the Division of Epidemiology at the UCSD
Department of Family and Preventive Medicine and Moores UCSD Cancer
Center; and William B. Grant, Ph.D., of the Sunlight, Nutrition and
Health Research Center, San Francisco.
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