2 new studies back vitamin D for cancer prevention

EurekAlert ^ | feb 6, 2007 | multiple - from UCSD

[caveat emptor]

2 new studies back vitamin D for cancer prevention

Two new vitamin D studies using a sophisticated form of analysis called meta-analysis, in which data from multiple reports is combined, have revealed new prescriptions for possibly preventing up to half of the cases of breast cancer and two-thirds of the cases of colorectal cancer in the United States......
"The data were very clear, showing that individuals in the group with the lowest blood levels had the highest rates of breast cancer, and the breast cancer rates dropped as the blood levels of 25-hydroxyvitamin D increased," said study co-author Cedric Garland, Dr.P.H. "The serum level associated with a 50 percent reduction in risk could be maintained by taking 2,000 international units of vitamin D3 daily plus, when the weather permits, spending 10 to 15 minutes a day in the sun."

[caveat emptor]

Here's the whole article: (except list of co-authors)

Two new vitamin D studies using a sophisticated form of analysis called meta-analysis, in which data from multiple reports is combined, have revealed new prescriptions for possibly preventing up to half of the cases of breast cancer and two-thirds of the cases of colorectal cancer in the United States. The work was conducted by a core team of cancer prevention specialists at the Moores Cancer Center at University of California, San Diego (UCSD), and colleagues from both coasts.

The breast cancer study, published online in the current issue of the Journal of Steroid Biochemistry and Molecular Biology, pooled dose-response data from two earlier studies - the Harvard Nurses Health Study and the St. George's Hospital Study - and found that individuals with the highest blood levels of 25-hydroxyvitamin D, or 25(OH)D, had the lowest risk of breast cancer.

The researchers divided the 1,760 records of individuals in the two studies into five equal groups, from the lowest blood levels of 25(OH)D (less than 13 nanograms per milliliter, or 13 ng/ml) to the highest (approximately 52 ng/ml). The data also included whether or not the individual had developed cancer.

"The data were very clear, showing that individuals in the group with the lowest blood levels had the highest rates of breast cancer, and the breast cancer rates dropped as the blood levels of 25-hydroxyvitamin D increased," said study co-author Cedric Garland, Dr.P.H. "The serum level associated with a 50 percent reduction in risk could be maintained by taking 2,000 international units of vitamin D3 daily plus, when the weather permits, spending 10 to 15 minutes a day in the sun."

The colorectal cancer study, published online February 6 in the American Journal of Preventive Medicine, is a meta-analysis of five studies that explored the association of blood levels of 25(OH)D with risk of colon cancer. All of the studies involved blood collected and tested for 25 (OH)D levels from healthy volunteer donors who were then followed for up to 25 years for development of colorectal cancer.

As with the breast cancer study, the dose-response data on a total of 1,448 individuals were put into order by serum 25(OH)D level and then divided into five equal groups, from the lowest blood levels to the highest.

"Through this meta-analysis we found that raising the serum level of 25-hydroxyvitamin D to 34 ng/ml would reduce the incidence rates of colorectal cancer by half," said co-author Edward D. Gorham, Ph.D. "We project a two-thirds reduction in incidence with serum levels of 46ng/ml, which corresponds to a daily intake of 2,000 IU of vitamin D3. This would be best achieved with a combination of diet, supplements and 10 to 15 minutes per day in the sun."

Vitamin D3 is available through diet, supplements and exposure of the skin to sunlight, or ultraviolet B (UVB). In the paper, the researchers underscored the importance of limiting sun exposure such that the skin does not change color (tan) or burn. For a typical fair-skinned Caucasian individual, adequate vitamin D could be photosynthesized safely by spending 10 to 15 minutes in the noontime sun on a clear day with 50 percent of skin area exposed to the sun. Darker skinned individuals may require more time in the sun, such as 25 minutes. For people with photosensitivity disorders, or anyone with a personal or family history of nonmelanoma skin cancer, any amount of extra sun exposure would be inadvisable.

The meta-analysis on colorectal cancer includes data from the Women's Health Initiative, which had shown in 2006 that a low dose of vitamin D did not protect against colorectal cancer within seven years of follow-up. However, the researchers wrote, the meta-analysis indicates that a higher dose may reduce its incidence.

"Meta-analysis is an important tool for revealing trends that may not be apparent in a single study," said co-author Sharif B. Mohr, M.P.H. "Pooling of independent but similar studies increases precision, and therefore the confidence level of the findings."

[Judith Anne]

Thanks for posting. I have read elsewhere that D has anti-inflammatory and some antiviral effects.

I'd think that natural D, made by the body in sunlight, is likely the best form for health maintenance.

[Razz Barry]

bttt

[caveat emptor]

I'd think that natural D, made by the body in sunlight, is likely the best form for health maintenance.

Me too. But it depends on where you live, and how much exposure to sunlight you can get.

I've seen studies showing a relation between latitude and these cancers in the western US. You're in good shape if you live in Phoenix. Not so good in Seattle.

[Harmless Teddy Bear]

For a typical fair-skinned Caucasian individual, adequate vitamin D could be photosynthesized safely by spending 10 to 15 minutes in the noontime sun on a clear day with 50 percent of skin area exposed to the sun

Well, I'll just strip down and run outside at lunch. It is only going to be 5 degrees out there. With the wind chill dropping it to -10 I should have a dandy case of frostbite.

Not that it would do much good. We aren't due to get any sunshine at all until next Monday. Maybe. Do all these researchers live in California?

[djf]

Exactly.
Vitamin D is made from the reaction between UVB light and Cholesterol. (You know, cholesterol, the stuff they say is so bad for you, even though your liver makes 85% of the cholesterol you have, and it is used in probably 3/4 of the biochemical processes in your body).

But UVB ONLY gets through the atmosphere if the sun is withing 30 degrees or so of the zenith.

Most of America only gets that for maybe three months a year.
Most Americans are woefully deficient in Vitamin D.

Just watch. Vitamin D will turn out to be one of the most important nutritional finds in the last century.
(fish oil and omega 3's being the next)

[Lil'freeper]

A Nutrition Ping List For Those Interested in the Research of Dr. Weston A. Price

'Everything old is new again' again ... and even survives meta-analysis.

[Hetty_Fauxvert]

Just to jump on board here, this article says: "Expectant mothers with the highest level of vitamin D intake - about 724 IU per day - had about half the risk of having a child who would have a wheezing illness at age three years of age, and less than half the risk of having a child at high risk for asthma, reported Carlos A. Camargo, M.D., Dr.Ph., of Harvard."

Interestingly, this article makes a similar claim for getting enough Vitamin E during pregnancy: "The study included 1,861 children whose mothers were recruited during pregnancy. The researchers surveyed the women on their diet habits during pregnancy and assessed children's diets and respiratory health at age 5. They found that children whose mothers had the lowest vitamin E intake during pregnancy were still more likely to suffer wheezing at age 5, and were about twice as likely to have doctor-diagnosed asthma."

(I saw another article on this subject that speculated that the mania for keeping peanut butter out of pregnant women's diets, because of fears of food allergies, might have the unintended result of causing asthma instead. I am particularly interested in the link between vitamins in pregnancy and childhood asthma, since my husband has asthma and I am pg!)

[djf]

I am firmly convinced (and have been for a while) that you simply cannot get everything you need from your diet, you need supplements.

To get the MDR of potassium, you'd have to eat like 5 baked potatoes a day. Then to get the vitamin C you need, you're looking at probably 8 to a dozen oranges. Add in all the other vitamins and minerals, and you're looking at a shopping cart full of food.

Don't forget the coconut oil and MCFA's!!
Lauric acid is important for the body, very high in coconut oil, Also very high in mother's milk.

[GovernmentShrinker]

Interesting. This could account for the much higher rates of asthma in "inner city" (read "black and Hispanic") children. Many leftist sources try to attribute this to socioeconomic disadvantage and resulting factors like higher pollution levels and cockroach infestation in poor city neighborhoods, but the combination of dark skin and poor nutritional habits may be the real culprit.

[Fairview]

This could account for the much higher rates of asthma in "inner city" (read "black and Hispanic") children. Many leftist sources try to attribute this to socioeconomic disadvantage and resulting factors like higher pollution levels and cockroach infestation in poor city neighborhoods, but the combination of dark skin and poor nutritional habits may be the real culprit.

What a very interesting idea. Thank you for bringing it forward. I've wondered for a long time about the interplay of reasons for this sad epidemic.

That said, I would not say it's necessarily "leftist" to ascribe higher rates of asthma among black children to poverty. Inner-city conditions do expose children to irritants like cigarette smoke and allergens like cockroaches, mold and dust. A well-intentioned but ignorant mother may not have the focus or the funds to do things to put her asthmatic child in a hypoallergenic environment (pillow and mattress covers, a HEPA vacuum cleaner, air filters, etc.)

It's also possible that the kids who might once have been removed from the gene pool through death are now helped by new drugs and treatments to stay alive so that they can have kids of their own, and those kids inherit the genetic predisposition to asthma.

But a mother who doesn't get enough Vitamins D and E during pregnancy can also give birth to a kid predisposed to asthma, and it's made worse when the child doesn't get outside to play during the day and needs extra outdoor time because he has dark skin. You have to assume they're getting enough Vitamin D-supplemented milk.

[Sam Cree]

"I'd think that natural D, made by the body in sunlight, is likely the best form for health maintenance."

It should follow then that people living in higher latitudes, where there is less sunlight, get less cancer. Although too much sunlight is obviously a cause of cancer as well, due to overexposure to UV rays, I think. 'Course, , in colder climates they eat a lot of cheese, which is also a source of vitamin D.

[Sam Cree]

people living in higher latitudes, where there is less sunlight, get less cancer...should say, "get more cancer"

Clearly not alert yet this morning.

[GovernmentShrinker]

That said, I would not say it's necessarily "leftist" to ascribe higher rates of asthma among black children to poverty. Inner-city conditions do expose children to irritants like cigarette smoke and allergens like cockroaches, mold and dust.

It's leftist to jump to the conclusion that economic factors are the primary cause of the difference in asthma rates between black and white children.

A well-intentioned but ignorant mother may not have the focus or the funds to do things to put her asthmatic child in a hypoallergenic environment (pillow and mattress covers, a HEPA vacuum cleaner, air filters, etc.)

True, but that has nothing to do with the fact that the child is asthmatic in the first place, just an issue of how effectively it's managed. It's the higher asthma rate in inner city kids that is notable. It's a given that all medical conditions will be less well-managed in that sort of environment.

[Varda]

Apparently higher cancer rates in the northern areas has been noticed before.

"This may explain, at least in part, why some studies dating back to the 1940s find that after adjusting for other factors, people in New England states have a higher overall cancer death rate than those in sunnier climates."
http://www.webmd.com/content/Article/77/95337.htm?pagenumber=2

[aruanan]

I'd think that natural D, made by the body in sunlight, is likely the best form for health maintenance.

Speaking as a Ph.D. in Human Nutrition/Nutritional Biology, I can tell you that a chemical is a chemical is a chemical. Sure, if you're able to take enough sun daily (without sun screen) and live in a place where there's enough sun of sufficient intensity throughout the year, you have nothing to worry about. However, supplemental vitamin D will do exactly the same thing as that synthesized in the skin and has already been shown to be necessary to prevent deficiency disease. It was the widespread incidence of rickets that led to the search for and identification of vitamin D. Since synthetic vitamin D was added to milk, the incidence of rickets has dropped dramatically. Now, if people were getting insufficient vitamin D to prevent rickets, then they were certainly getting far too little vitamin D for its other roles that require a lot more than for preventing the deficiency disease.

[Ladysmith]

Say, on the advice of another, I just started using coconut oil. I've been trying to find more information about it and its benefits. Do you have some good links or information you can pass on to me?

[Varda]

A chemical may be a chemical but is there a difference in the way the body behaves when its taken orally versus through the skin. For instance transdermal estrogen is metabolized better than estrogen that has to take a pass through the liver.

[editor-surveyor]

Thanks for the ping.

[aruanan]

For instance transdermal estrogen is metabolized better than estrogen that has to take a pass through the liver.

Apparently it's not a matter of metabolism but its action on certain processes in the liver:

The dissociation of the GH/IGF-I axis by the oral route is likely to arise from impaired hepatic IGF-I production which causes increased GH secretion through reduced feedback inhibition. The route of oestrogen therapy confers divergent effects on substrate oxidation and body composition. The suppression of lipid oxidation during oral oestrogen therapy may increase fat mass while the fall in IGF-I may lead to a loss of lean body mass. The route dependent changes in body composition observed during oestrogen replacement therapy may have important implications for post-menopausal health and oestrogen use in general.
--Metabolic effects of oestrogens: impact of the route of administration.,
Ho KK, O'Sullivan AJ, Wolthers T, Leung KC.
Ann Endocrinol (Paris). 2003 Apr;64(2):170-7.

In the case of vitamin D, it is the precursor that is produced in the skin, not the vitamin. It is metabolized in the liver into the vitamin form. Oral vitamin D precursor is absorbed and similarly metabolized in the liver into the same active form.