Lack of vitamin D increases the aggressiveness of colon cancer
16 August 2011
Researchers at the Vall d’Hebron Institute of Oncology (VHIO),
in collaboration with the Alberto Sols Institute of Biomedical Research
(CSIC-UAB), have confirmed the role of vitamin D in inhibiting colon
The indication that vitamin D and its derivatives have a protective
effect against various types of cancer is not new. Numerous
experimental and epidemiological studies have shown that vitamin D3
(or cholecalciferol) and some of its derivatives inhibit the growth
of cancerous cells.
This study has confirmed the pivotal role of vitamin D,
specifically its receptor (VDR), in slowing down the action of a key
protein in the carcinogenic transformation process of colon cancer
cells. The results are being published in the journal PLoS One.
This protein, known as beta-catenin, which is normally found in
intestinal epithelial cells where it facilitates their cohesion,
builds up in large quantities in other areas of the cells when the
tumour transformation begins. As a result of these changes, the
protein is retained in the cell nucleus, where it facilitate the
carcinogenic process, and this is the point at which vitamin D
intervenes, or rather, the vitamin D receptor (VDR).
“Our study has confirmed the pivotal role of the VDR in
controlling the anomalous signal that sparks off the growth and
uncontrolled proliferation of colon cells which, in the final
instance, ends up causing a tumour to emerge”, says Héctor Palmer,
the coordinator of this study and head of the VHIO’s Stem Cells and
Cancer laboratory. He continues, “The stimulation of this receptor
suppresses the action of the beta-catenin protein, intercepting the
series of events that change the intestinal cell into a malignant
The study was conducted on mice and human colon cancer cells. The
mice were used as a model to replicate the initial phases of colon
“These findings show that mice of this kind, which also lack the
VDR and hence do not respond to vitamin D, present larger and more
aggressive tumours than mice with the VDR”, explains Dr. Palmer, and
concludes: ”The number of tumours is not influenced by the absence
of VDR, which would indicate that this factor does not protect
against the appearance of the tumour but does intervene in its
growth phase, reducing its aggressiveness”.
The researchers then analysed the effect of the VDR on human
colon cancer cell cultures and observed that the concentration of
the altered protein, beta-catenin, increased in cells without the
VDR. These findings were repeated in the three types of colon cancer
cells studied, and confirmed the results observed in the mice.
In two-thirds of advanced colon cancer tumours there was a lack
of VDR in the cancer cells, and this circumstance leads us to
believe that this loss may contribute to speeding up the growth of
the tumour. The findings of this study confirm this supposition.
Vitamin D: essential in the initial phases of colon
In light of these findings, chronic vitamin D deficiency
represents a risk factor in the development of more aggressive colon
tumours. Patients in the initial stages of colon cancer, the time
when the VDR still has a substantial presence in the cells, could
benefit from being treated with vitamin D3. However, this would not
be useful in the advanced stages of the disease when the presence of
the VDR is very much reduced.
The study data support the development of anti-tumour medicines
based on the structure of vitamin D, although their use in patients
will require further research in the next few years.
The body not only obtains vitamin D from food, especially milk
and fish oils, but also manufactures it from exposure to sunlight.
Prolonged exposure is not necessary; just 10 minutes in the sun
every day when it is not at its peak is sufficient to stimulate its
production. During the summer, when we are more likely to sunbathe,
it is important to use the appropriate protective measures against
sunburn to avoid future sun damage. Use high-factor solar protection
products and do not expose the skin to the sun in the middle of the
day to protect against skin cancers.