Vitamin D and Cancer Prevention
Vitamin D and Cancer Prevention
In recent years, many doctors and researchers have struggled to find a cure for cancer. Researchers are currently investigating treatments; not only to cure cancer but also prevent its development before it starts. One such strategy is known as chemopreventive treatment, which is the use of certain chemicals and drugs(both natural and synthetic), to limit the spread of cancer and possible prevention of it.
Surprisingly, one of the most useful and effective chemopreventive treatments is Vitamin D and its analogs. Statistics have shown that women with low vitamin D intake or low direct sunlight(which causes natural vitamin D synthesis) have a higher mortality rate from breast cancer. According to these studies, such women are also more likely to develop breast cancer early in life. This data has led both researchers and doctors to further investigate the potential chemopreventiveness of vitamin D and its analogs.
Clinical trials testing vitamin D and its effects on cancer are rare. The Women’s Health Initiative(WHI) is currently in mid trial of their Clinical Trials and Observational Study of Vitamin D and Cancer, which is set to end later this year(Vijayakumar et al, 2006). This study is testing the effects of vitamin D on Colorectal and Breast Cancer in postmenopausal women(ages 50-79), throughout the world. Researchers are using a vitamin D supplement in this 1:1, double blind study of about 45,000 women. They hope their results will show a decreased risk of colorectal and breast cancer in those who took the supplement, compared to those who received the placebo. Previous studies found minimal benefits of vitamin D on cancer. Although, researchers believe the results of their studies could be faulty, because many trial participants had to withdraw from the study due to hypercalcemia.
This represents one of the major road blocks in the study of vitamin D as a chemopreventive drug. Vitamin D controls the amount of calcium in the blood and how much is taken up by the bones. With too much vitamin D, calcium can build up in the body to very unhealthy levels.
One can only hope that such research can turn out positive results and a possible cure for cancer. Future studies that use vitamin D analogs, such as vitamin D5 (which is a less harmful version of vitamin D), seem to be the most promising. As for now there is no cure for cancer, but there is always hope.
Source:
Clinical Trials Using Chemopreventive Vitamin D Analogs in Breast Cancer, Dr. Vijayakumar, et al, The Cancer Journal, Vol. 12 No. 6 November/ December 2006
Posted by: JMcNeill
Update 2/20/07
First, I would like to thank everyone who read and posted comments on my blog. They were all very helpful, and the questions were great.
Many of you were curious to know what is a healthy amount of Vitamin D to take. Most doctors and medical professionals suggest taking 1,000-1,300 mg per day for adults and even more for adolescence and elderly. Most of the previous studies on Vitamin D and its effects on cancer used doses slightly higher than the 1,300 mg, about 1,500 mg. Researchers found that such a high dose for a prolonged period of time caused hypercalcemia.
Researchers started testing the body’s threshold for Vitamin D in the early 1990's. Since then research has been fairly steady, with the most recent study being started is 1998 by the Women’s Health Initiative(WHI). The study done by the WHI, is the only study, according to the article, that is test Vitamin D’s effect on Colorectal and Breast cancer.
In response to some of your other questions, too much Vitamin D and Calcium does not cause cancer. In fact it only causes hypercalcemia and excess build up of Calcium in the bones which may cause joint tenderness and weakness. Most drugs on the market to combat hypercalcemia due so by limiting the absorption of Calcium by the small intestine. Therefore it would negate the effects of Vitamin D, which promotes the synthesis and absorption Vitamin D. It was asked, since most Vitamin D is gained via sunlight, why not use sunlight of UV lamps to gain Vitamin D? The answer to this is fairly simple, most of the studies of Vitamin D’s effect on cancer are done with patients who either already have cancer (Breast Cancer in particular) or have pre-curses to cancer. As we already know, it has been proven that too much exposure to UV rays(in sunlight) can cause skin cancer. Thus researchers do not want to take the extra and un-needed risk by exposing the these patients to potentially harmful UV rays. They simply do not want to prevent one type of cancer by causing another.
Posted by: JMcNeill
2/20/07
posted by PWH @ 4:09 PM
6 comments
6 Comments:
I found this post very interesting because I am interested in cancer. Isn't it ironic that low direct sunlight is related to a higher mortality rate in breast cancer, but too much sun is a cancer risk factor. Moderation is best. When you said that not many studies have been done on this, it made me think of that vitamin "one a day for women" which advertises that it has Vitamin D to promote breast health. It makes the lay person think that Vitamin D is safe to take. I happen to take the generic brand of this vitamin myself so that struck me. It has 400IU of Vitamin D. What is considered a good amount to take?
Sarah G. Biology 101
Breast cancer seems to run in my family so this article was of interest for me. I never would have thought that a vitamin taken daily could possibly help prevent or slow the effects of cancer. The title of the article is very decieving because it doesn't let you know what kind of cancer, but when you read further you come to find that it is leaning more towards breast cancer. Auto-immune diseases are also very common in my family and my mother, being a nurse practitioner, started having my family take vitamin D pills. She told us that we were more likely to get another auto immune disease and she heard somewhere that D would help prevent that happening. I don't know if a study was done about this, or a fellow colleague advised her to do this, but there must be something good about this Vitamin D.
I find it very interesting that Vitamin D is related to the prevention of cancer. I always knew that having the right amount of vitamins in your body is healthy, but I didn't know that it was THIS important. Since not having enough Vitamin D in your body calcium increases in your body, does that mean that too much calcium has to do with getting cancer? Also, besides breast cancer, what other kinds of cancer does taking Vitamin D help reduce the risk? Or is that not even known yet? How long has this research been going on for? This blog post was very interesting to me, not only because my family has a history of breast cancer but also because it's something that sounds very promising for future cancer prevention. It was direct, easy to understand and well written.
I’m glad that I read this blog. I never knew that vitamin D could help prevent breast cancer. Maybe I’ll start spending more time outside. You said that vitamin D could cause an unhealthy calcium buildup. I wonder if there is a way to counteract that, possibly with another drug. I was also wondering how much/often you would have to take extra vitamin D for it to be effective.
I found it really interesting that the previous trial showed little benefit from vitamin D, yet they are doing another study. If sunlight regulates viatamin D levels, why don't they put people under sunlamps....it works for people with depression. If this problem can lead to breast cancer, then why don't they put more vitamin D in pills like "Centrum".
"Vitamin D controls the amount of calcium in the blood and how much is taken up by the bones. With too much vitamin D, calcium can build up in the body to very unhealthy levels."
Well even with a surplus of Vitamin D if one lacks sufficient calcium in their diet there won't be an excessive build up of calcium. In this day and age most of the country does not get enough calcium in their diet.
Our bodies have a negative feedback mechanism system that maintains the calcium concentration in our plasmas at approximately 10mg. In the event that our bodies have an excessive amount of caclium (which is very rare in adults) the protein hormone calcitonin inhibits osteoclastic activity thus decreasing the calcium concentration.
VK Biology 101
Post a Comment
<< Home