According to a recently published study shows that, the higher the levels of vitamin D in a person system’s, the lower the risk of cancer.
In a study recently published in the British Medical Journal, researchers found that the highest levels of vitamin D in the body are associated with a 20% reduction in the risk of cancer. The relationship is found in both men and women and evolves according to vitamin D levels up to a maximum limit beyond which its effect becomes zero.
Vitamin D is a quasi-hormone synthesized from a precursor that is found in the diet and must be activated under the influence of ultraviolet rays. A poor diet and modest sun exposure are associated with low levels of vitamin D in the body.
While the essential role of vitamin D is recognized for calcium absorption in the intestine and its attachment to the skeleton, its role is more controversial in other diseases.
Experimental studies have shown that vitamin D, and especially its activated form, 1,25-dihydroxyvitamin D would have an anti-proliferative effect on tumor cells through multiple signaling pathways of the cell, involved in stopping the tumor cell cycle, creation of blood vessels and inflammation. And these effects have been reported on cancers of the colon, breast, prostate mainly.
The protective effects of vitamin D against cancer are much more controversial in clinical studies and the results of epidemiological studies are contradictory.
The is the largest study measuring 25-hydroxyvitamin D levels in the blood of men and women with cancer ever conducted. It involved more than 30,000 Japanese men and women who were followed 16 years, including 3301 with cancer and they were compared to 4044 comparable people.
The participants were in their forties at inclusion. Its results took into account all the factors that could have disrupted the validity of the analysis, such as age, sex, weight, seasons, alcohol consumption, smoking, etc…
The reduction concerns most cancers except the lung and the prostate, but it is also observed even more importantly with liver cancer, the liver being the organ that makes 25-hydroxy-vitamin D.
Compared to the previous ones, this study collects the largest number of vitamin D measurements made in a study to date and shows that, within the limits of physiology, the higher the level of vitamin D in the blood, the lower the risk of cancer. Beyond the physiological limits, the increase in vitamin D levels does not lead to any reduction of cancer risk.