A vitamin D deficiency would be a factor in bladder cancer, according to British researchers who have reviewed several studies. This is a direct association with the immune system.
Vitamin D plays an essential role in the body as it facilitates the absorption of calcium through the intestinal mucosa and the fixation of calcium on bone. Food supplies only low amounts of vitamin D: they are mainly found in fatty fish (tuna, mackerel, herring, sardines, salmon ...) and non-skimmed dairy products.
In addition, vitamin D is synthesized in the skin exposed to the sun, and is stored in the liver. It is for this reason that these reserves are at their lowest level in late spring.
The Inpes * states in particular that a "deficiency of vitamin D can be observed in the subjects not very exposed to the sun like the infants, the elderly living in institutions, the people confined in their residence, those living in the Regions of low sunlight or those with dull skin ".
It is recommended to consume at least twice a week fatty fish and to enjoy without benefit the benefits of sunlight but despite these recommendations it is not uncommon to have a lower level of vitamin D and supplementation Be advised under medical supervision.
Vitamin D deficiency modulates the immune response
Because it is proven that vitamin D deficiency can have a significant negative effect on bone mineral density, which in particular increases the risk of osteoporosis and fractures in the elderly. But researchers at Warwick University evoke another risk, still little studied: that of bladder cancer.
Their work indicates that they reviewed seven studies on the subject, which varied between 112 to 1125 participants each. Five out of seven studies correlated low levels of vitamin D with an increased risk of bladder cancer but did not quantify the risk threshold. In an experiment conducted by their own care, the researchers then have the cells that line the bladder, known as transitional epithelial cells.
They found that these cells are able to activate and respond to vitamin D, which in turn stimulates an immune response. Although this combination has to be proved by other clinical studies, it is important because the immune system plays an essential role in preventing cancer by identifying abnormal cells before they develop and become cancerous.
Beneficial or deleterious effects to be studied more closely
"Low levels of vitamin D in the bloodstream can prevent bladder cells from stimulating an adequate response to abnormal cells," says Dr. Rosemary Bland, lead author of the study. "Because vitamin D is cheap and safe, Potential use in cancer prevention is exciting and could have an impact on the lives of many. "
It is not the first time that the link between a low serum level in vitamin D and cancer is evoked, but no study has been able to prove it despite suspicions about colorectal and breast cancer. In this regard, the National Cancer Institute confirms that vitamin D "is also involved in hormonal production, modulating the immune response and controlling cell proliferation."
In fact, these properties could "make it possible to envisage a potential role in the processes of carcinogenesis". However, given the available data, it recommends further investigations to determine more precisely its possible role as a protective but also a risk factor. Indeed, studies must also be carried out to study the effect of high doses on the organism.
* National Institute of Prevention and Education for Health