It has been known for a long time that there are less of some types of cancers in people who live in the sunbelt vs those who live in areas with weaker sunlight. This is thought to be due to higher levels of vitamin D. Now there research that suggests a new mechanism for the role of vitamin D. Does low vitamin D, make cells less sticky and promote cancer?
In the US, those that live in the south have a lower overall risk of cancer, with certain types of cancer including prostate and bone cancers, having a significantly lower incidence.
More recently, research has suggested that vitamin D has an anti-cancer role. As more evidence has accumulated, most researchers feel that low levels of vitamin D increase the overall risk of getting cancer.
As an example, a review of a number of studies on cancer, determined that having adequate vitamin D levels will decrease the risk of colon cancer by 50%.
Additionally, there is evidence that those having cancer surgery and treatments in the summer have an increased chance of surviving over those who have surgery or treatments in the winter. It has been suggested that this is due the fact that most people have higher levels of vitamin D in summer.
Vitamin D, often called the sunshine vitamin, is made in our skin in response to strong sunlight, or can be obtained from a few foods, or in supplements. Vitamin D is found in cod liver oil (which is also high in vitamin A and so the correct dose should not be exceeded), fish, and fortified foods, including dairy products.
A new model (Garland, C Annals of Epidemiology, 2009, in press) suggests a potential mechanism for the role of vitamin D. Cancer arises when cells change and stop behaving normally. One thing that happens is that cells stop communicating normally with the cells around them. This disrupted communication which is know as disjunction, may enable cancer cells, which are more aggressive than normal cells, to take over an area. The model suggests that in a low vitamin D environment that cells are less sticky and so a cancer can develop more easily.
Whether this model is correct or not, it is clear that everybody should get enough vitamin D, either from the sun or from supplements.
photo credit: Jon Haynes Photography
[tags]vitamin D, cancer, anti-cancer, sunbelt, skin[/tags]
