Vitamin D

http://news.independent.co.uk/world/science_technology/article335359.ece


Revealed: the pill that prevents cancer

By Jeremy Laurance, Health Editor

Published: 28 December 2005

A daily dose of vitamin D could cut the risk of cancers of the breast,
colon and ovary by up to a half, a 40-year review of research has
found. The evidence for the protective effect of the "sunshine vitamin"
is so overwhelming that urgent action must be taken by public health
authorities to boost blood levels, say cancer specialists.

A growing body of evidence in recent years has shown that lack of
vitamin D may have lethal effects. Heart disease, lung disease, cancer,
diabetes, high blood pressure, schizophrenia and multiple sclerosis are
among the conditions in which it is believed to play a vital role. The
vitamin is also essential for bone health and protects against rickets
in children and osteoporosis in the elderly.

Vitamin D is made by the action of sunlight on the skin, which accounts
for 90 per cent of the body's supply. But the increasing use of
sunscreens and the reduced time spent outdoors, especially by children,
has contributed to what many scientists believe is an increasing
problem of vitamin D deficiency.

After assessing almost every scientific paper published on the link
between vitamin D and cancer since the 1960s, US scientists say that a
daily dose of 1,000 international units (25 micrograms) is needed to
maintain health. " The high prevalence of vitamin D deficiency combined
with the discovery of increased risks of certain types of cancer in
those who are deficient, suggest that vitamin D deficiency may account
for several thousand premature deaths from colon, breast, ovarian and
other cancers annually," they say in the online version of the American
Journal of Public Health.

The dose they propose of 1,000IU a day is two-and-a-half times the
current recommended level in the US. In the UK, there is no official
recommended dose but grey skies and short days from October to March
mean 60 per cent of the population has inadequate blood levels by the
end of winter.

The UK Food Standards Agency maintains that most people should be able
to get all the vitamin D they need from their diet and "by getting a
little sun". But the vitamin can only be stored in the body for 60
days.

High rates of heart disease in Scotland have been blamed on the weak
sunlight and short summers in the north, leading to low levels of
vitamin D. Differences in sunlight may also explain the higher rates of
heart disease in England compared with southern Europe. Some experts
believe the health benefits of the Mediterranean diet may have as much
to do with the sun there as with the regional food.

Countries around the world have begun to modify their warnings about
the dangers of sunbathing, as a result of the growing research on
vitamin D. The Association of Cancer Councils of Australia acknowledged
this year for the first time that some exposure to the sun was healthy.


Australia is one of the world's sunniest countries and has among the
highest rates of skin cancer. For three decades it has preached sun
avoidance with its "slip, slap, slop" campaign to cover up and use
sunscreen. But in a statement in March, the association said: "A
balance is required between avoiding an increase in the risk of skin
cancer and achieving enough ultraviolet radiation exposure to achieve
adequate vitamin D levels." Bruce Armstrong, the professor of public
health at Sydney University, said: " It is a revolution."

In the latest study, cancer specialists from the University of San
Diego, California, led by Professor Cedric Garland, reviewed 63
scientific papers on the link between vitamin D and cancer published
between 1966 and 2004. People living in the north-eastern US, where it
is less sunny, and African Americans with darker skins were more likely
to be deficient, researchers found. They also had higher cancer rates.

The researchers say their finding could explain why black Americans die
sooner from cancer than whites, even after allowing for differences in
income and access to care.

Professor Garland said: "A preponderance of evidence from the best
observational studies... has led to the conclusion that public health
action is needed. Primary prevention of these cancers has been largely
neglected, but we now have proof that the incidence of colon, breast
and ovarian cancer can be reduced dramatically by increasing the
public's intake of vitamin D." Obtaining the necessary level of vitamin
D from diet alone would be difficult and sun exposure carries a risk of
triggering skin cancer. "The easiest and most reliable way of getting
the appropriate amount is from food and a daily supplement," they say.

The cost of a vitamin D supplement is about 4p a day. The UK Food
Standards Agency said that taking Vitamin D supplements of up to
1,000IU was " unlikely to cause harm".

What it can do
Heart disease

Vitamin D works by lowering insulin resistance, which is one of the
major factors leading to heart disease.

Lung disease

Lung tissue undergoes repair and "remodelling" in life and, since
vitamin D influences the growth of a variety of cell types, it may play
a role in this lung repair process.

Cancers (breast, colon, ovary, prostate)

Vitamin D is believed to play an important role in regulating the
production of cells, a control that is missing in cancer. It has a
protective effect against certain cancers by preventing overproduction
of cells.

Diabetes

In type 1 diabetes the immune system destroys its own cells. Vitamin D
is believed to act as an immunosuppressant. Researchers believe it may
prevent an overly aggressive response from the immune system.

High blood pressure

Vitamin D is used by the parathyroid glands that sit on the thyroid
gland in the neck. These secrete a hormone that regulates the body's
calcium levels. Calcium, in turn, helps to regulate blood pressure,
although the mechanism is not yet completely understood.

Schizophrenia

The chance of developing schizophrenia could be linked to how sunny it
was in the months before birth. A lack of sunlight can lead to vitamin
D deficiency, which scientists believe could alter the growth of a
child's brain in the womb.

Multiple sclerosis

Lack of vitamin D leads to limited production of 1.25-dihydroxyvitamin
D3, the hormonal form of vitamin D3 which regulates the immune system,
creating a risk for MS.

Rickets and osteoporosis

The vitamin strengthens bones, protecting against childhood rickets and
osteoporosis in the elderly.

A daily dose of vitamin D could cut the risk of cancers of the breast,
colon and ovary by up to a half, a 40-year review of research has
found. The evidence for the protective effect of the "sunshine vitamin"
is so overwhelming that urgent action must be taken by public health
authorities to boost blood levels, say cancer specialists.

A growing body of evidence in recent years has shown that lack of
vitamin D may have lethal effects. Heart disease, lung disease, cancer,
diabetes, high blood pressure, schizophrenia and multiple sclerosis are
among the conditions in which it is believed to play a vital role. The
vitamin is also essential for bone health and protects against rickets
in children and osteoporosis in the elderly.

Vitamin D is made by the action of sunlight on the skin, which accounts
for 90 per cent of the body's supply. But the increasing use of
sunscreens and the reduced time spent outdoors, especially by children,
has contributed to what many scientists believe is an increasing
problem of vitamin D deficiency.

After assessing almost every scientific paper published on the link
between vitamin D and cancer since the 1960s, US scientists say that a
daily dose of 1,000 international units (25 micrograms) is needed to
maintain health. " The high prevalence of vitamin D deficiency combined
with the discovery of increased risks of certain types of cancer in
those who are deficient, suggest that vitamin D deficiency may account
for several thousand premature deaths from colon, breast, ovarian and
other cancers annually," they say in the online version of the American
Journal of Public Health.

The dose they propose of 1,000IU a day is two-and-a-half times the
current recommended level in the US. In the UK, there is no official
recommended dose but grey skies and short days from October to March
mean 60 per cent of the population has inadequate blood levels by the
end of winter.

The UK Food Standards Agency maintains that most people should be able
to get all the vitamin D they need from their diet and "by getting a
little sun". But the vitamin can only be stored in the body for 60
days.

High rates of heart disease in Scotland have been blamed on the weak
sunlight and short summers in the north, leading to low levels of
vitamin D. Differences in sunlight may also explain the higher rates of
heart disease in England compared with southern Europe. Some experts
believe the health benefits of the Mediterranean diet may have as much
to do with the sun there as with the regional food.

Countries around the world have begun to modify their warnings about
the dangers of sunbathing, as a result of the growing research on
vitamin D. The Association of Cancer Councils of Australia acknowledged
this year for the first time that some exposure to the sun was healthy.


Australia is one of the world's sunniest countries and has among the
highest rates of skin cancer. For three decades it has preached sun
avoidance with its "slip, slap, slop" campaign to cover up and use
sunscreen. But in a statement in March, the association said: "A
balance is required between avoiding an increase in the risk of skin
cancer and achieving enough ultraviolet radiation exposure to achieve
adequate vitamin D levels." Bruce Armstrong, the professor of public
health at Sydney University, said: " It is a revolution."

In the latest study, cancer specialists from the University of San
Diego, California, led by Professor Cedric Garland, reviewed 63
scientific papers on the link between vitamin D and cancer published
between 1966 and 2004. People living in the north-eastern US, where it
is less sunny, and African Americans with darker skins were more likely
to be deficient, researchers found. They also had higher cancer rates.

.

Relevant Pages
Loading