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Vitamin D can decrease -- or increase -- breast cancer development and insulin resistance (20K IU?)
Georgetown University Medical Center ^ | April 4, 2011 | Unknown

Posted on 04/04/2011 7:15:45 AM PDT by decimon

Researchers say their mice study should provide a word of caution to people who believe that excess vitamin D prevents cancer

Orlando, Fla. -- In mice models of breast cancer, researchers at the Georgetown Lombardi Comprehensive Cancer Center, a part of Georgetown University Medical Center, found that vitamin D significantly reduced development of estrogen receptor-positive (ER+) breast cancer both in lean and obese mice, but had no beneficial effect in estrogen receptor-negative (ER-) cancer. In fact, obese mice destined to develop ER- breast cancer were clearly worse off than lean ER- mice if they were given vitamin D in their diet.

The researchers, who will present their study at the American Association for Cancer Research (AACR) 102nd Annual Meeting 2011, also found that vitamin D reversed insulin resistance in obese mice, no matter which breast cancer subtype they later developed. In lean mice, however, there was no evidence that vitamin D increased insulin sensitivity.

"Use of vitamin D supplementation is clearly tricky. In the many studies that have been done studying the effect of vitamin D in different cancer types, there is no straight link between use and benefit," says the study's lead investigator, Leena Hilakivi-Clarke, Ph.D., a professor in the Department of Oncology.

For example, in the colon, vitamin D seems to reduce the risk of cancer development, but it may not have any effect on later stage colon cancer. There is also concern that vitamin D may increase the risk of prostate, esophagus and pancreatic cancer. In work she has conducted in endometrial cancer, Hilakivi-Clarke found that although vitamin D was not beneficial in lean mice, in obese animals it reverses both early and advanced stages of the cancer.

"This is not a vitamin that should be taken lightly," she cautions. "People need sufficient amounts because it has beneficial effects for overall health that have nothing to do with preventing cancer. But for those who want to boost their use of vitamin D, it is important that they have their individual levels tested by a physician, and that they discuss their desire to use supplements."

IMPACTS OF VITAMIN D INTAKE IN MICE MODELS (findings in Hilakivi-Clarke lab)

Lean mice Obese mice ER+ breast cancer Risk reduced Risk reduced ER- breast cancer Dose dependent benefit No benefit Insulin resistance No benefit Reversed Endometrial cancer No benefit Risk reduced


Colon cancer Reduces risk of development; No effect on later stage cancers

Pancreatic, esophageal, prostate cancers Potentially increases risk

In their ER- breast cancer study, the researchers fed lean mice two doses of vitamin D - 15 or 20 K international units [IU] VD3 - from puberty onset onwards for 24 weeks. They found that the lower dose (15 K IU) of VD3 significantly reduced mammary tumor incidence as well as time for tumors to develop in lean mice, when compared to mice that were fed control diet. A higher dose (25K IU) was used in mice fed the obesity-inducing diet because vitamin D becomes trapped in fatty tissue and thus is reduced in the blood stream, Hilakivi-Clarke says. Obese mice destined to develop ER- cancer that were given vitamin D developed the highest incidence of breast cancer.

In their ER+ breast cancer, only the higher vitamin D dose (20K IU) was used. This dose significantly reduced breast tumor incidence in lean mice, compared to control or obese animals. Additionally, obese mice fed vitamin D developed fewer tumors than obese mice not supplemented with it, says Hilakivi-Clarke.

In both mouse models of breast cancer, obese mice developed insulin resistance, and vitamin D supplementation reversed it. However, vitamin D in lean mice tended to reduce insulin sensitivity in both mouse models, she says.

The researchers are currently studying possible mechanisms by which vitamin D may reverse obesity induced increase in breast cancer and insulin resistance, and preliminary results suggest vitamin D reverses the action of genes which promote inflammation, cell proliferation and survival, and this might involve epigenetic modifications.


The study was funded by Department of Defense and National Cancer Institute, a part of the Department of Health and Human Services. The authors report having no personal financial interests related to the study

About Georgetown Lombardi Comprehensive Cancer Center

The Georgetown Lombardi Comprehensive Cancer Center, part of Georgetown University Medical Center and Georgetown University Hospital, seeks to improve the diagnosis, treatment, and prevention of cancer through innovative basic and clinical research, patient care, community education and outreach, and the training of cancer specialists of the future. Lombardi is one of only 41 comprehensive cancer centers in the nation, as designated by the National Cancer Institute, and the only one in the Washington, DC, area. For more information, go to

About Georgetown University Medical Center

Georgetown University Medical Center is an internationally recognized academic medical center with a three-part mission of research, teaching and patient care (through MedStar Health). GUMC's mission is carried out with a strong emphasis on public service and a dedication to the Catholic, Jesuit principle of cura personalis -- or "care of the whole person." The Medical Center includes the School of Medicine and the School of Nursing and Health Studies, both nationally ranked, the world-renowned Georgetown Lombardi Comprehensive Cancer Center and the Biomedical Graduate Research Organization (BGRO). In fiscal year 2009-2010, GUMC accounted for 79 percent of Georgetown University's extramural research funding.

TOPICS: Health/Medicine; Science
KEYWORDS: cancer; diabetes; health; medicine; type2diabetes; typeiidiabetes; vitamind; vitd
This story is making the rounds and will probably show up on Free Republic a few times. I don't understand the dosages. 15,000 IU in a mouse? Is that 15,000 IU daily? I'd think that would kill a mouse.
1 posted on 04/04/2011 7:15:47 AM PDT by decimon
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To: neverdem; DvdMom; grey_whiskers; Ladysmith; Roos_Girl; Silentgypsy; conservative cat; ...


2 posted on 04/04/2011 7:16:25 AM PDT by decimon
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To: decimon; austinmark; FreedomCalls; IslandJeff; JRochelle; MarMema; Txsleuth; Newtoidaho; ...
Bump & a type 2 diabetes ping

FReepmail me if you want on or off the diabetes ping list.

3 posted on 04/05/2011 12:19:28 PM PDT by neverdem (Xin loi minh oi)
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To: neverdem

Lots of diabetes, malignant brain tumors and other cancers in my mother’s side of the family. I am in fact quite old for a member of this family, by almost 10 years.

This is interesting.

Thanks for the ping.

4 posted on 04/05/2011 12:31:01 PM PDT by TheOldLady
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To: decimon

Thanks for the ping.

15,000 IU? I’m with you. That would kill a mouse.

I’ve been taking 5000 IU of D3 daily for three years. It hasn’t made a difference in the way I feel. However, and I realize this is 100% anecdotal, I haven’t been sick a day since I started.

I think Big Pharma will denigrate any study showing good results with cheap, common meds. They want is to spend big bucks on their meds.

5 posted on 04/05/2011 12:33:07 PM PDT by upchuck (Think you know hardship? Wait till the dollar is no longer the world's reserve currency.)
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To: decimon

Some years ago while in school, I read about a study that was performed to see if coffee had cancer-producing (or -inducing) properties.

They experimented on mice, and found there was a positive inclination to this.

The kicker was, over time they’d stuffed the mice with 37 pounds of coffee!

Even back then, that was an astonishing read for me.

So take from this what you will.

Personally, I take 4K IUs daily in the summer (I’m outside a lot), and up that to 8K in the winter.

While I do take a lot of other supplements, my doctor says he likes what I’m doing with this, so for now, anyway, I’m staying with it.


6 posted on 04/05/2011 12:55:56 PM PDT by Chances Are (Seems I've found that silly grin again....)
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To: decimon

My son takes 2500 - 5000 IU of D-3 daily for help with symptoms of ADD. It seems to work quite well.

7 posted on 04/05/2011 1:49:35 PM PDT by kimmie7 (I do not think BO is the antichrist, but he may very well be 665.)
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To: decimon; neverdem

There is so much more they don’t know. They find these correlations and assume causation. I would like to see how often they account for age when they are calculating risk for disease. Increasing age is the number 1 risk factor for most diseases. Everyone develops hardening of the arteries, higher blood pressure, higher blood sugar, and usually gains weight as they age. If you find an 80-year-old with heart problems and high cholesterol, well, I would say his age is more important than the cholesterol as a risk factor for heart disease. There is a normal human lifespan, and no amount of tinkering is going to give us a bunch of youthful 95-year-olds. Sometimes “abnormal” numbers don’t mean much.

This is an example of what I mean and is relevant to the discussion of vitamin D.

8 posted on 04/05/2011 10:37:57 PM PDT by Pining_4_TX
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To: decimon

Very interesting. I found out about three months ago my vitamin D 3 was seriously low. Started taking prescription supplements (Hectorol) and the D levels gradually rose and most astonishing, my cholesterol and triglycerides and glucose became normal for the first time ever!

Very good news, because I hate statins and Diabetes 2 meds. Perhaps everyone should be tested for Vitamin D 3 25-hydroxy levels!

9 posted on 04/06/2011 7:44:27 AM PDT by varina davis (Life is not a dress rehearsal)
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To: upchuck

Does it help with allergies?

10 posted on 04/07/2011 1:43:43 PM PDT by diamond6 (Check out: and learn about the faith.)
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To: diamond6
Does it help with allergies?

Yes! I've noticed a decrease in my desire for sex :)

Seriously, I have a few pollen related sniffles. Nothing serious. And I've noticed no change.

11 posted on 04/07/2011 4:36:04 PM PDT by upchuck (Think you know hardship? Wait till the dollar is no longer the world's reserve currency.)
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To: nnn0jeh

ping to post 9

12 posted on 04/07/2011 4:45:47 PM PDT by kalee (The offences we give, we write in the dust; Those we take, we engrave in marble. J Huett 1658)
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