Friday, May 16, 2008

Does Vitamin-D Prevent Breast Cancer?

In the US this year, breast cancer is the most common cancer in women on which about 184,450 cases and 40,930 deaths from this disease are expected.

According to a Canadian research, breast cancer patients with low levels of vitamin D were much more likely to die or have it spread the disease, than those patients who were getting enough of the nutrient — adding to evidence the "sunshine vitamin" has anti-cancer advantage. Blood samples were taken from about 500 women at three University of Toronto hospitals from the period, 1989 and 1995, when these women were first diagnosed with early-stage of breast cancer. The results are sure to renew arguments, whether a little more sunshine is a good thing. They wanted to see if ever it has made a significant difference in the patients’ survival.

After 10 years, 83% of those who had sufficient vitamin-D blood levels were alive without extensive spread of their cancer, compared to 79% of those whose vitamin-D levels were inadequate and 69% of those who were deficient, as defined by medical standards widely used for measuring intake.

It was just 24% of women in the study had sufficient blood levels of vitamin-D at the time they were first diagnosed with breast cancer. Those who were deficient were nearly twice as likely to have their cancer recur or spread over the next 10 years, and 73% more likely to die of the disease. This was released Thursday by the ASCO and will be presented at the group's annual meeting later this month.

The head of the study, Dr. Pamela Goodwin of Mount Sinai Hospital in Toronto, said, “These are pretty big differences … It’s the first time that vitamin D has been linked to breast cancer progression … But people shouldn't start downing supplements, she warned … there may be an optimal level of vitamin D in women with breast cancer and it may be possible to take too much …”

There are substantial disagreements among experts on how much vitamin D people need or the best way to get it, and too much can be harmful. They also don't know whether getting more vitamin D can help when someone already has cancer. Though the study was too small and those results were not conclusive. The federal government says up to 2,000 international units of vitamin D a day seems OK.

Goodwin explained, taking 800 units per day will, on average, raise blood levels to the middle of the range that seems best for bone and general health, "It's very hard to make a recommendation" because how much difference a supplement makes depends on someone's baseline level, which also can be affected by sunlight, skin type and time of year. Doctors do suggest breast cancer patients get their vitamin D levels checked to see whether they are deficient. The simple blood test is available in many hospitals and labs for modest amount.

But according to Dr. Julie Gralow, a cancer specialist at the University of Washington in Seattle, "We have no idea whether correcting a vitamin D deficiency will in any way alter these outcomes."

Dr. Nancy Davidson, a Johns Hopkins University cancer specialist who is president of the oncology society, said those tests are growing in popularity, even in ordinary medical care. She said,"Rightly or wrongly, I'm increasingly seeing physicians who are measuring this."

Dr. Larry Norton, chief of breast cancer programs at Memorial Sloan-Kettering Cancer Center in New York and a medical adviser to the foundation, said, “It's a very provocative paper. It's confirmatory of a tremendous amount of evidence that vitamin D is an important component of health."

Lots of earlier research suggests vitamin D may help prevent prostate, breast and especially colon cancer. In lab and animal tests, vitamin D represses abnormal cell growth, curbs formation of blood vessels that feed tumors and has many other anti-cancer effects.

Other evidence: People who live in northern regions of the world have higher cancer rates than those living closer to the equator, possibly because of less sunshine and vitamin D. One red flag: The few women with the very highest levels of vitamin D seemed to have worse survival.

Vitamin D can be found in egg yolk, beef liver, salmon and other oily fish, and milk. The skin makes vitamin D from ultraviolet light. Too much sunlight can raise the risk of skin cancer, but small amounts — 15 minutes or so a few times a week without sunscreen — may be beneficial, many doctors believe.

While the vitamin is found in certain foods and supplements, most do not contain the best form, D-3 nutrient, which have the modest effect on blood levels.

Despite a lot of questions and the need for further studies, lest we should not forget the age-old adage, “An ounce of prevention is better than a pound of cure.” Is Vitamin-D the answer to this?

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Ria Coleto-Cervantes said...

This is a very informative and I am glad you have shared it. Great article!

How's things Aor? Pretty busy? Have a nice day pal!

Ria (It's my Party and I'll cry if I want to...)

Ria Coleto-Cervantes said...

Hi Aor,

You're tagged!