what is the link between vitamin D and cancer

I was deficient in vit D
I was deficient in vit D when diagnosed also not sure why they are linked.

John23 said:

Vitamin-D
Is there a role for vitamin D in reducing cancer risk?

A large number of scientific studies have investigated a possible role for vitamin D in cancer prevention.

The first results came from epidemiologic studies known as geographic correlation studies. In these studies, an inverse relationship was found between sunlight exposure levels in a given geographic area and the rates of incidence and death for certain cancers in that area. Individuals living in southern latitudes were found to have lower rates of incidence and death for these cancers than those living at northern latitudes. Because sunlight/UV exposure is necessary for the production of vitamin D3, researchers hypothesized that variation in vitamin D levels accounted for the observed relationships.


Evidence of a possible cancer-protective role for vitamin D has also been found in laboratory studies of the effect of vitamin D treatment on cancer cells in culture. In these studies, vitamin D promoted the differentiation and death (apoptosis) of cancer cells, and it slowed their proliferation.


Randomized clinical trials designed to investigate the effects of vitamin D intake on bone health have suggested that higher vitamin D intakes may reduce the risk of cancer. One study involved nearly 1,200 healthy postmenopausal women who took daily supplements of calcium (1,400 mg or 1,500 mg) and vitamin D (25 μg vitamin D, or 1,100 IU―a relatively large dose) or a placebo for 4 years. The women who took the supplements had a 60 percent lower overall incidence of cancer (6); however, the study did not include a vitamin D-only group. Moreover, the primary outcome of the study was fracture incidence; it was not designed to measure cancer incidence. This limits the ability to draw conclusions about the effect of vitamin D intake on cancer risk.

A number of observational studies have investigated whether people with higher vitamin D levels or intake have lower risks of specific cancers, particularly colorectal cancer and breast cancer. Associations of vitamin D with risks of prostate, pancreatic, and other, rarer cancers have also been examined. These studies have yielded inconsistent results, most likely because of the challenges of conducting observational studies of diet (7). Information about dietary intakes is obtained from the participants through the use of food frequency questionnaires, diet records, or interviews in which the participants are asked to recall information about their dietary intakes. Information collected in this manner can be inaccurate. In addition, only recently has a comprehensive food composition database with vitamin D values for the U.S. food supply become available. Other dietary components or energy balance may also modify vitamin D metabolism (8).

Measuring blood levels of 25-hydroxyvitamin D to determine vitamin D status avoids some of the limitations of assessing dietary intake. However, vitamin D levels in the blood vary by race, with the season, and possibly with the activity of genes whose products are involved in vitamin D transport and metabolism. These variations complicate the interpretation of studies that measure the concentration of vitamin D in serum at a single point in time.

Finally, it is difficult to separate the effects of vitamin D and calcium because of the complicated biological interactions between these substances. To fully understand the effect of vitamin D on cancer and other health outcomes, new randomized trials will need to be carried out (9). However, the appropriate dose of vitamin D to use in such trials is still not clear (10).
From here: Vitamin D and Cancer Prevention: Strengths and Limits of the Evidence


I personally don't believe in manufactured vitamins. Vitamin D is made
by our own body when we are in direct sunlight. Ingesting it, simply isn't
the same thing; the body processing isn't there. The body works best when
it's allowed to work on it's own.

Me..... my body's retired.... So I just sit in the sun and soak up beer.
Oh yeah, and sunshine.

Good thoughts,

John

up
up

coloCan said:

Two relatively recent articles on Vit D and CRC:
cancernetwork.com/print/article/10165/1636781?printable=true dated 8/10/10 entitled:
"Colorectal cancer patients with vitamin D deficiency see worse outcomes."

and at site coloncancer.about.com for article entitled : Higher Blood Vitamin D levels, Better Survival After Colon Cancer."

Latter states: People with blood vitamin D levels of 15 ng/ml (nanograms per milliliter) or higher had 84% better chances of surviving after colon cancer surgery compared with those who had vitamin D levels of 7 ng/ml or less."

Also, just put out by Mayo Clinic this afternoon
in article entitled "Research Finds Insufficient Vitamin D Levels in CLL Patients Linked to Progression and Death", tho dealing with vitamin D and chronic lymphocytic luekemia,(CLL), the following is also stated:

"This research adds to the growing body of evidence that vitamin D deficiency is a risk factor for development and/or progression of a number of cancers,the researchers say. Studies have suggested that low blood vitamin D levels may be associated with increased incidence of colorectal,breast and other solid cancers. Other studies have suggested that low vitamin D levels at diagnosis may be associated with poorer outcomes in colorectal,breast,melanoma and lung cancers, as well as lymphoma."........